I haven't played POE1: what are the specific differences between the two games that make you feel that way?
Hmm, do take note that these are personal impressions, rather than precise calculations.
For start, the modifier pool of the items seems to be diminished significantly, and the crafting mechanics are reduced dramatically. PoE has always had massive RNG elements in its crafting, but over the years, more and more systems were introduced to deterministically influence the outcome, to the point of some mechanics(that ended up being rightfully nerfed) being straight up item-editors. I haven't gotten deep into endgame due to time constraints, but from what i've seen, items in PoE2 are more similar to D4 than they are to PoE.
Passive tree seems a lot more boring while simultaneously being harder to pass through, stuff like tree masteries was a riot when it got introduced in PoE, while in 2 they're just gone without a mention, and while that may very easily change, for now i don't see good reason for traversing into entirely-different corners of the tree.
Which, actually, combined with skill gems being one-weapon-locked, seems like a deliberate push deeper into class-segregated system, something GGG has tried to do for a while now in PoE, but couldn't achieve fully.
I could continue rambling, but in general, PoE is
wacky. It's perfect for making stupid shit work.
And the same sentiment just doesn't seem to apply to 2. And, yeah-yeah, i know, early access, half of the classes and 2/3 of ascendancies aren't in the game, PoE took years to get to the wacky state it's in today, and EA status implies things will change, but i feel like these are deliberate design decisions that aren't changing, at least not for a few years.
And, contrary to the impression i may leave with the post, i like PoE2 a lot. Visual design, audio design, overall aesthetics are gorgeous, and i actually do enjoy the somewhat-slower pace of the gameplay loop. But the degradation in complexity is real and that makes long-term investment into the game much less alluring for me.