Just ignore the game mode. Matchmaking is broken at the boundaries. GP is a failed measure of whatever it is they're trying to measure with it. It accurately measures nothing. Just realize that if you participate in the mode, you are likely to get match-ups that seemingly make zero sense to you and that you've made choices that are not conducive to being successful in the game mode.
Ironically, this point is used by some of the same posters on here who also strongly advocate for the limited GP matching we currently have as opposed to the GA matchmaking. Apparently those choices deserved a free pass, but not chasing the meta doesn't. Relative, it is, mmmm?