[Xeen]

I'm going to give a concise example:

MMA vs MC, GSTL game 7 betwen oGs and SlayerS. MC in a series at that time is heavily favored. Yet the game was incredibly exciting because it was so pivotal, and because MMA pulled out all the stops to clinch a win.

Spectators don't want to see the superior player get lots of chances to conservatively clean up. They want to see underdogs come out and try to pull something wild to upset their superior opponent, while the set is still not a disappointing league upset because it's bo7 team vs team.

Individual leagues and team leagues both give multiple games per set to fairly decide the better competitor. Similarly, like a single player might have many strategies to select for their games, a team has different players to send out. Same concept, larger scale - and Proleague has always run effectively on the system.

That's not to say the bo5 of bo3s doesn't work, but I'd definitely argue it lacks the same degree of spectator appeal.