Mystic, for me, is perfect. That answers the question posed. Boats? AMYA? The RC plane guys’ magazine is 80% competition - but the remaining 20% has everything in the model aviation world. I think AMYA is probably about the same. Where would I get a chance to sail my Robbe Atlantis? My buddy’s AC boat?
The racers are the most vociferous group, while the scale or recreational guys are typically more laid back.
My only opinion would be that boats of roughly the same size sail together…