I honestly feel D4 has improved a lot lately, maybe even surprassed LE

I have around 400 hours in LE, and probably a little bit more than that in D4. (and 3000 hours in Grim Dawn).

D4 is much more fluent in combat. The engine is a lot better than anything on the market bar Grim Dawn (tactile response, visual "oomph" of skills, impact of hits, ragdolling, etc) so slaying creatures feels much more fun and doesn't get old as quick.

It has better music, better lore and atmosphere than most ARPGs, too. What was lacking was endgame, itemization, build diversity and non-existent "skill trees".

Out of those issues, I think itemization was largely fixed (still not D2/POE tier, but it's decent now, we need more unique items like Tempest Roar tho - that is, build enabling) and build diversity is at its all time high, possibly surpassing LE which suffers HORRIBLE balance issues (Falconer, ward meta, etc.).

The endgame activities are also more varied compared to monolith meta of LE.

D4 still BADLY needs "skill tree" rework, more unique items and better pinnacle boss (Lilith is more of a meme - no real rewards, which I find lame). It also needs more skills. I think new expansion will bring a few new skills to existing classes and supposedly new uniques as well - if this trend is continued, D4 MAY finally offer multidimensional classes. Although it will be hard to beat LE's Runemaster.

I'm still on the fence with some of the design choices, but I can't say the game is not improving. And I think that it's the most fun ARPG to play, together with Grim Dawn, when it comes to action. PoE is unbeatable in terms of build diversity, itemization and community (trade. etc.) but doesn't feel as mechanically enjoyable as D4/GD.

LE is honestly disappointing to me. All the complex skill trees are sort of undone by horrible balance, and the engine is really bad - no ragdolling, floaty combat, feels like a cheap mobile game and gets old really fast. Hopeflly it will get better with time.