(a consequence is PoE2 having some of the worst gear in all RPG),.
How....???? That's a gold standard of item design.
Not only you get a wide range of unique weapons, that can compliment variety of role-play and builds but they stay relevant throughout the entire game. While in Baldur's Gate2 there is a handful of items you will actually use on multiple playthrough.
Then again, I don't find +4 weapons, to be an exciting change from +2 weapon. I would rather keep the balance stabe but add unique properties... as PoE2 did.