Why consolidate FFA ranked?

I find matches pretty easily in high platinum/low diamond matches. Is the change because of matchmaking for those onyx and above? Why not consolidate the billion team playlists you got in all the Halos? I don’t mind the new non slayer modes coming, but I don’t see why FFA has to die and we have to play a whole new game rule set. FFA is one of the main reasons I play game online so I hope mythic doesn’t suck or else I’ll have nothing to play outside of 1v1.