Weekly challenges are bad
In the tomes each level only unlocked every 2 weeks, however each tome had 4 levels with like 17 to 20 challenges per level. Assuming on average 18.5 means 74 challenges. The new weekly system seems like it has 12 times 5 challenges for 60, so less but close. However it seems like there is always a "complete 3 quests challenge" in there. That would be like counting the ending dots on tomes. So in reality we get 48 challenges, from on average 74. That is a decrease by roughly 35%.
In addition to that, if you wanted to complete the challenges you would need to play multiple games, which encouraged you to play the way, and many challenges encouraged you to do that in a varied playstyle. I easily completed all of this weeks challenges in 4 games. Since one week would have been half a tome level, it means I needed less than half the games to beat these weeklies compared to the tome.
Sure, there are dailies but I have yet to get a daily that is not quite literally just completed by playing the game. I miss old dailies because they actually encouraged you to play the game.
You could also put out milestones, but I played most of my games for quests over the past two weeks and I am already on level 6 or higher on all but 1 of my milestones.
Yeah, old tome challenges also had challenges that were just "play the game", but now the proportion of these quests are way way more common.