@Fietta while I don't disagree with most of your point's I think you are looking at this too logically, yes on paper each round becomes more important however overall in a tournament scenario it's completely different.
I don't want to reiterate some of herishey's and others points, however I would like to bring to light some bits of empirical evidence where we have tried this before, once was the PTK and I know the bracket was wrong but you still didn't change it and went ahead with the shit decision (very worrying).
Second is a Marxeil and I think Wursti tournament, don't remember the format but it was one big group with a round based system and I distinctly remember winning based of a single round with PB in a match against a Russian team and that was the deciding factor.
It felt garbage to win like we hadn't achieved what we wanted, in addition to that I remember we 7-0 snappers and they really did get unlucky in our match and despite them going on to beat cazadores (who we almost lost to) they ended like 5th in the bracket.
IMO with so few teams in what is an extremely volatile competitive format as others have stated some rounds can go the other way it seems to me like you really are just causing unnecessary drama and trouble.
@Blitz in football its based on 90 minutes + extra time instead of a points limit so a counter argument would be with more time the other team might have won, just like saying well with more rounds we might have won. There is a limit set for a reason it's the first to reach it, it doesn't matter how you got there.
Point's being the decider makes far more sense.