I love Diablo. However, I think a big part of it is the atmosphere and also me being young and never having seen anything like it. That’s pretty hard to recreate. I heard the game Halls of Torment nailed the Diablo atmosphere, but as a Vampire Survivors-like. Basically it’s focused on the grind and progression. Maybe, that’s something for you? Personally, I haven’t found anything that is as fun as Diablo, so every now and then I play Diablo 1 with a new mod, like the new The Hell 3 Mod. It brings back the wonder of the unknown, because there is lots of new stuff in there. I also loved Book of Demons, which is basically a streamlined version of Diablo 1 with a dark comedic twist.
I think you underestimate the satisfaction that comes from clearing levels in Diablo. Yes, it could be a different theme and still work, but isn’t that proof of how potent it is? So the question is, why does it feel like a grind to you? I wager it’s because the magic Diablo had for you got lost over time. You know how they work now, you’ve seen behind the curtain and thus don’t feel the danger, the intrigue like you used to. Maybe you will find it in games like Elden Ring that you don’t see through right away?
About the stats progression: I think a very big part of the fun of progressing your character comes from doing it the way you want. It’s a form of expression. You want to be a Necromancer that only uses Golems or a Mage focused on ice. I think what a lot of Diablo-likes miss is finding a good way to allow lots of expression in character development. Too often I feel boxed in by the class and it doesn’t feel like it’s my Tinkerer, but the Tinkerer instead. A good Diablo-like has abilities that define the character instead of just simple stat increases and cooldown reductions and all that.
Lastly, if you haven’t seen it there is a great Diablo 4 Critique on YouTube that might give some more food for thought!