there is a best though, and it's the player who beats the consensus upper-tier sparrers most consistently
it's never hard to see who the best is, it only becomes unclear when people intentionally avoid and hide away from others

Player A beats Player B + Player B beats Player C doesn't automatically = Player A is better than Player C, don't have to be a rocket scientist to understand match-ups, but it becomes pretty obvious who the best is when there is enough people sparring and the sample size is big enough to where there are clearly dominant players

a singles tournament wouldn't necessarily prove it either, but it'd be one step closer than just talking about it