>>56308127It's a JRPG mechanic that has several sub-bosses before the final boss fight, but other than that it has no purpose.
This is why it's handled differently in the anime, more like positions obtained by merit and beating them doesn't guarantee you a position, just like a champion beating another champion doesn't steal their position, it's just done for ranking purposes. For example, Ash beating Leon in WPC gave him the title of world champion, but not the title of Galar champion, which Leon keeps.
I think the developers realized this inconsistency and that's why in SV Champion is more a title of your level as a trainer than a real position, unlike Geeta's job, which is a real position with obligations.