FC25 Online Friendlies Matchmaking Feels Broken and Unfair

I think one thing you didn’t mention is casuals are not playing it. I would guess the majority of players are in d3-elite. While I am sure some d10 players will play it probably not many. 

Casuals first have to play what 10 or more rush games 14 squad battle games and 15 rivals on average.  Then wl is less casual but also hours and hours of trading sbcs evos.  So your pool of matchmaking is going to be harder to begin with.