It's enough of this broken GAC matchmaking!!!!

Don't expect it to change.  They haven't done anything with GAC for at least 3 years now.  No matter what, one player wins and one player loses.  They pay out the same rewards either way in GAC and TW. 

Their priority is selling us "new shiny" stuff.  GAC and TW are old.  Same as many bugs, old and not a priority if they only impact players negatively.  The accountants are in charge at CG.

There is the same problem in Chromium II and III as well. Be glad you were in Kyber when the squish happened . Others were not so fortunate.

Fr im playing against ppl with gp's like 8 mill more then my acc

I more often than not have the lowest GP in my bracket, so feel I have experience with these situations.  I have empathy for those playing in the lower leagues and coming across larger accounts.  I think something needs to be done, when a player's account is significantly larger than the divisions average

However, I have zero sympathy for a player that's moved up the leagues and then complaining about playing accounts bigger than theirs; this is how it should work.   The fact the nuance of your complaint is it's been happening over an extended period (+6 months), also suggests your holding your own.....just you don't like it or think it's unfair.

Also remember that in GAC, there's no way of using your full GP, so it's a measurement as a fairness tool.  The system we have works very well 'if' all players are putting in the same amount of effort.  Sadly, it does fail when players only play now and again or have periods of not playing.

I think what we have not is infinitely better than the old system.  Where we deliberately min-maxed our roster as to not bloat the GP.  This is an awful situation for a collectible game.  And where players like you (and maybe I)  would got 11-1/12-0 (used to be for rounds to a GAC) each month.  That truly sucks for our mirror mate going 1-11/0-12.

"entire brackets where the lowest is 10M (maybe one player), and everyone else is at least 12M. From Kyber to Aurodium."  I'd like to see proof of brackets outside of mid-high K3 consistently above where 6 of the 8 are 'at least' 12M.  I don't believe this is the case at all.

TLDR

Fix larger GP accounts in lower leagues - definitely.   Fix smaller GP accounts in higher than original leagues - no way.