I haven't really tried AF FS2021 yet, just took a quick look if there are really other aircraft flying around - there are. Traffic will bring a completely new dimension to this sim, so maybe I will come back from desktop.
But with traffic there will be other, new questions: TCAS? Slots for take-off and landings? Will other aircraft land where I am about to take off, in the other direction, of course? Mid-air collisions? I guess I will find out about all that, but maybe there are already answers out there.