Personally after hanging out with alot of competitive drifters. My main gripe would be lack of classes and the extremely rare occurrence of s1 lobbies. I have been beaten by quite a few rwd drifters in an awd car. Thats mainly what I do in fh5 too. Awd does generate more points but not as much as a person may think if your skilled enough.
A class doesnt have as much variety as S1 car wise
Im not saying I disagree with the rwd awd separation of lobbies… Its just its not as bad as people think it is. I have cycled for a S1 lobby for an hour straight before. To not completely fill this post I shared my thoughts in more depth here in the past. Open Drifting: Similar Setup to Forza Horizon 4's Drift Adventure (B-S2 RWd/AWD Restriction)
Rereading now though alot of it is quite outdated as some things were corrected/fixed since this post 