I think most players have pretty positive opinions on both Challenge Modes (essentially just precursors to M+ we have today) and the Mage Tower bosses.
I just wanted to take a moment to point out that not only are the rewards particularly cool, but that they are IMPORTANT for the game.
Players obviously enjoy cosmetics. Understanding that, it’s easy to see how “cool stuff” can inspire players to tackle content they might not ordinarily be up for. They help inspire players to play better, because you want that cool stuff, right?
Well, “play better” often equates to “play more”, because those Mage Tower bosses in particular could eat up a lot of time. I also enjoyed running some of the higher M+ content at the end of Shadowlands (really didn’t play Dragonflight).
Now, there are obviously new armor sets and weapon designs coming at the game at all times. I still haven’t touched TWW, but the Arathi armor and weapons all look sick. But I would obviously receive those effectively from just buying the expansion; there’s no special effort required. As such, as cool as it may look, that lack of any real effort leaves them feeling kind of meaningless.
As someone who used to be a pretty hardcore raider back in the day, the things that motivate me are rewards that are cool that also require a lot of personal investment to achieve. Back in MoP, I knew I had to get the CM set for Warlocks, which inspired me to hunker down and really play that character at a high level. Once I spent the time learning them inside and out, I enjoyed it so much I wound up making them my main for the remainder of the expansion.
I love the “Mage Tower” approach specifically, because it gives you something you can do totally by yourself, which is just a nice thing to jump into an hour or two before raid-night starts.
I imagine those are quite difficult to make and balance, so I totally get those aren’t something that can we created too regularly. But I think having cool rewards locked behind difficult challenges helps give that “carrot-on-a-stick” that keeps you pushing to master your class, and I find myself really looking for something like that to draw me into TWW.