Competitive teams only: In other words, teams for competitive battling with other people or the advanced post-game sections like Battle Tree or Pokemon World Tournament. No teams for regular gameplay.
But what about speed runs? I'd say they ain't regular gameplays. Although, these peculiar teams aren't used for battling other trainers. They don't complete Battle Tree or whatever either. The same rule counts with nuzlockes or any locke that doesn't give you any random Pokémon. They ain't used for, again, battling other trainers. and people usually don't go to Battle Tree or anything else. Besides of course, Red or Blue, that's a must have of course.
That's all! SeeYaLater!