Gears 4 did this too.
why are diamonds matched with teams full of silvers?
No other competitive game does this (cs go,rainbow six siege, league of legends, street fighter v, online chess)
The whole point of a ranking system is that you are matched with people equal to your skill level.
Of course you cant always guarantee an equal match in rank due to playerbase and que time reasons.
Noobs are getting steamrolled and there is no learning experience.
Ultimately rank in gears is meaningless as it is just a little picture that changes in the ranking menu.