i actually thing the F/s meter is more for casual play more than this community.
The main reason I think it was, at least originally, designed for competitive play, is that competitive players have made it clear that anything that has any degree of randomness to it will not be allowed in competitive play.
Smash Balls are random as hell. So like every other item, they get turned off. But Final Smashes are actually a big part of a character's identity, and a the pinnacle of their moveset. All of that is lost by simply switching them off.
The solution was to add a super meter like every other fighting game has, that removes all the randomness from getting your FS. Unfortunately, as we've seen, even after ATTEMPTING to balance them for the meter, a lot of them are still OP. Which probably led them to going, "Well, we'll just say it's for fun then. Maybe we'll figure out the balance in time for Smash 6."
Sometimes though, I wonder if a character's FS being OP might not be a part of their overall balance. Like, a character that's lacking in other areas, could be balanced out by having a stronger FS, and then a large part of their gameplay strategy becomes focused on building their FS meter.