I wish DbD had offline minigames like Duck Game
Duck Game has a lot of weird, niche mechanics you'd never know about until someone with 1000 hours more experience than you have use it on you, and even then you wouldn't be able to practice it until you get lucky and get put in the same situation. Just like how the chance to practice flashlight saves by yourself is not only rare, but will also likely set your team back if you fail. Which you probably will, if you're practicing.
Duck Game fixes that by having an offline arcade where you practice one simple mechanic, with a score for how well you do. You'd never know that sliding with a chainsaw makes you sprint, or that using a chainsaw on a wall makes you jump, unless you had the chance to practice in a race track designed for it. https://www.youtube.com/watch?v=D-YchCuybOM
The same thing for DbD would be fantastic for newer players who don't like to binge YouTube tutorials and get stomped by people with thousands of hours more than them, trying to learn the basics.
It's not hard to imagine a minigame where survivors need to loop tightly around generic tilesets, letting them think "How can I shave a couple seconds off so I can get a better time?" Or a minigame where survivors are very far away, and you need to hit them across the map as Huntress to let people get used to cross-map Hatchets. https://www.youtube.com/watch?v=8keh3gl5Zdg
I know this is a pipe dream, since it took them like 6 years from release to add bot matches, but it would make the game feel so much better. Instead of asking two friends to hop into an offline game, why not make a minigame that says "get as many flashlight saves as you can with one flashlight"? That'd teach you Flashlight timing, battery life, and how to maximize the uses out of one flashlight.