There is nothing deep about the D2 skill tree. And the attributes were a joke even when D2 released.
So a new wheel really is needed.
Not that I think what they have shown so far is the right solution. Quite far from it actually.
Give me skill choices with a bunch of (10+) skill modifications. Like Last Epoch or Wolcen.
As for attributes, I personally dont care much. Every single attribute system in an A-RPG has been trash. So maybe dont try. But if you try, then look at what Pillars of Eternity (a CRPG) did. With attributes that are actually useful for all classes, where you can make a strength barb, an int barb, a dex barb etc.
For itemization, look at something like Grim Dawn.
It is possible to learn things from Diablo 2. It has a really good overall package of gameplay. Not best at anything, nor worst.
But honestly, when looking at individual game features, it has been surpassed in nearly everything. One of the only things D2 has left is its world building, maybe also its strong class fantasies. While D1 got its great atmosphere. Take those into D4 for sure.
As for D2 with better graphics. Yeah, I want a D2 Remaster. I will pay good money for that.
But it sure isnāt what D4 should be.