So now that every viable regression/slowdown perk has been nerfed for Killers...

Whether that's a good news or bad news is in question

It's more there's a lack of alternatives. The nerfed perks are still the best choices but honestly this game on the most part has been balanced towards the side that wants to win more. There's so many ways to tilt the odds in your favor at the cost of variety between killers that are much stronger then the rest, map offerings and loads of other toys.

I do dislike the term 'gen rush' though because what else are the survivors supposed to do if they aren't getting chased? Are people really that conditioned by some players they get matched up against doing their throw the game tomes? The tomes that try to make the game seem like it has more depth then it actually does? It's gens, chases and hooks. Very little else most of the time. This is why slow down is so dominant. Because chase perks in general don't shorten chases enough to outperform slowdown perks. For example can you imagine if Bamboozle was 100% vault speed or something? Chases simply wouldn't feel rewarding for either side. That's a simple example but you could extend that to similar perks.

because big majority of the killer perks have no effectiveness. gen speed is still ultra oppressive.

I do think that a lot of killer perks can offer a ton of value. At least in public lobbies, where a majority of survivor teams are not as coordinated.

Many people just stick to what they deem to be the only solution and become blind to other options.

I just tried this build and has a ton of success:

-bloodwarden

-Alien instinct

-Franklin's demise

-weaving attunement

Really good info in item heavy lobbies and very good on killers with movement abilities like Singularity and Vecna.

Even if it's not gonna stop tunneling but…
What if survivor need to search for something before doing a gen? Like Oil, gasoline, …

Well I played a lot of Vecna since he's out and other than games where 2-3 people have 5-10k hours I don't really feel pressured at all. The only slowdown I have is corrupt because of his start-up time.

well that being said I'm not playing without tunneling but mostly just because I choose the best target if I have to choose between one dead and one on first hook. I won't search for the death-hook specific xD

People tend to link regression nerfs and potential slowdown nerfs together, which I think isn't appropriate. I don't think those two problems are even really that equivalent, let alone actually linked in that direct a way.

For the sake of transparency, I define genrushing as this: Survivors who bring in the strongest tools for making generators go as quickly as possible, at the cost of not having tools for most other elements of the game. Genrushing is not survivors that just do generators efficiently when they're not in chase at either default speed or default plus one perk speed. That's just playing the game normally.

With that in mind, it's not as though genrushing actually happens that often. Don't get me wrong, it's a problem when it does happen and even separately from genrushing toolboxes are too strong, but we can immediately see that something which affects a majority of games in a very obvious way - stacking regression perks - is a higher priority and doesn't need to be fixed at the exact same time as a problem you rarely see.

At the same time, and as a consequence of that, it's also pretty clear what the answer to the title question is. What will killers do now that slowdown perks are nerfed? They'll just… keep playing like normal. Most games are games where good play alone is enough slowdown, so even if we were to assume there are no viable slowdown perks left, there wouldn't really be a huge problem here.

Which is where it becomes relevant that there are still viable slowdown perks. There aren't even that many unviable slowdown perks, even something like Ruin has its place in certain builds.

Regression Perks were a reaction to escalating Repair Times.
And instead of adjusting how different factors impact repair times BHVR, as usual, sided with Survivors and decided to nerf Regression.

And now people are surprised that killers still run regression Perks. Of course they do. They didnt use them because it grinded repairs to a halt, they used them because it was necessary slowdown to a game where within 1 minute of starting the game you could get multiple gen pops.
You didnt give them a reason to not use regression perks, you just reinforced the fact that they need them.

How is that relevant to my post?
I said nothing about tunneling.
And even if I said something about Tunneling.
Yes, some Killers tunneled even with better slowdown perks, but it's delusional to pretend nerfing those slowdown perks did not increase tunnelling as a reaction.

It's simply a chain of reactions
Gens started to pop too fast → Slowdown became meta → Slowdown was nerfed → Slowdown loss is compensated with tunneling
And that is because instead of looking at why solo survs were popping Gens in the first minute of a game, BHVR saw Slowdown as a problem.
Tunneling wasn't part of this conversation, until Slowdown was nerfed because now Killers feel like they need a new tool.
That some Killers were intentionally tunneling even before isn't part of the equation because tunnelling came into this discussion as a consequence to a nerf that was based on a reaction to a shift in gameplay.

The more legitimate ways to achieve your goals you nerf or remove, the more people will instead rush to the low hanging fruit.
Sure, giving Killer alternatives or Rewards for different playstyles is not going to eliminate tunnelling forever, but it is miles better than just nerfing everything and then have surprise Pikachu Face when Tunneling, Camping and slugging become the main ways killers win again.

So what is your point here? "Wha wha, tunneling is a thing?`"
Yeah, and it will keep being a thing. At least as long as people use their endurance to tank hits for their unhooker instead of using it as actual protection against tunneling.

I always try to avoid tunneling but I don't mind to do it consistently and on purpose

Although, since I'm now slugging everyone, tunneling isn't exactly on the table.

My last few matches haven ended with one or two survivors bleeding-out and the others dying on their first hook.

Its' all fine.

That's true but those that used 1-2 regression perks might double down and use 3 or more now. That's what happens each and every time you nerf a meta without providing any alternative. Playing killer without slowdown doesn't really work and now that Pop and Pain Res were nerfed heavily it should come to no surprise when people will use even more slowdown than before to make up for that.

Given that the reason why these perks were nerfed was a high pick rate, I'd say they failed spectacularly.

Well, that's different.

If you can only have two regression perks, just for example, then you don't even need alternatives. People will just run different stuff because they can't run more regression since they're hard-locked out of it.

I don't think hard-locking people out of perks is the right way to go. It should be more like No Mither + Self Care. Yes, you can run both but why would you? It makes no sense. Anyway, BHVR wanted to shake up the meta by nerfing the most popular killer perks and they failed. There are multiple ways to achieve it but if we want to change the meta, then we'll need an alternative.

I would have thought Chaos Shuffle would have revealed this to most people but apparently not.

Not that I disagree with you about killer perks being good overall, but there are killer perks that are detrimental to you. The biggest example is Predator, which actively makes tracking over any real distance much harder.

There also aren't that many actively detrimental survivor perks. Maybe No Mither if you don't have some kind of plan or build for it? Fact is, either way on that specific example, most survivor perks are perfectly usable. The same notion of the top few perks skewing everyone's perception of useful applies there too.