Well obviously. But that makes for a very small competitive scene. Because pug systems couldn't exist/work without regulations.
I'm just saying that there's no need to mechanically enforce them. It's nice, but far from necessary. Smash and Pokemon had thriving comp with advanced regulations before online was even an option and there were no ways to enforce rules. Tabletop games have literally no way to enforce rules built in. People just play that way. The only two things you need for a comp scene are players and organizers. People willing to do the work and people willing to play.
These are also predominantly one against another games. Team based games where you throw 12 people split between two teams... It wouldn't exactly be that easy to keep it clean. I realize you could say "just don't play with them" but a pug finder- well you can't really choose who you play with. When I say pug finder I meeeean... Team fortress stadium TfCenter Cevo Faceit ESEA All that jazz.