the best thing about the whole series
the best thing about the whole series
You fourth word answers your own question
Propably because it had no dynamic ticket-bleed, no comeback-mechanics and SBMM/EOMM didn't work as they intended.
They're saying they removed content for "matchmaking health" but when playercount was 30% lower than today it wasn't an issue. And most players would prefer a proper server browser over their biased matchmaking anyways... full insane decision to remove paid main game content to push their free modes xD