If you mean enabling random option this becomes pretty common from like 1400 or 1500 I guess and the higher you go the more common it get to a point where on 1800 I’d say around three quarters of games are random civ.
Also might depend in maps.
Mega random is pretty obvious candidate.
In my experience people tend to play random on their favorite maps.
If I unban arabia most games are random.
If I ban arabia and get the classic nobody wants this one map oftentimes I don’t get random.
If I get arena it’s almost always random (apart from some turk pickers but that’s essentially the same 2 or 3 guys).
That’s at least a pattern I observed.