Because this game was never pointed as a multiplayer-oriented. It's not a PoE. THIS NOT AN MMO. It is a single-player game, where you can occasionally play Co-Op and have the most simple trading functionality. Nothing more and will never be because realisation of things you suggested takes too much resources. Basically, you have to change game's servers infrastructure and connect all of them together.
You have simple desync bugs while playing on 130+, what global chat are you talking about, lol.

This will never happen.
Read carefully:
never ever

This is a big mistake..
If this is the game intent, just remove the online part completely: it should have solved all the issue you talked in 0 time.
Actually today the situation is a lot better and I'm not having any particular big issue.

My latency in Europe is 23-25 ms (and I play from Italy with server in Frankfurt).

The issue that seems latency at the beginning to me was actually the fact that rolldodge does not interrupt skills, so you've to stop the skill you're doing before rolldodging (you cannot i.e. keep a skill pressed to repeatedly doing damage and rolldodge istantly when you want).
Other than that I play since 2 weeks and I've had no issue (I'm playing online of course, that's why I do miss a chat).