

Games as a Service wasn’t even the fatal flaw here. Brawlhalla is another platform fighter that is doing just fine off that model. The dev team for MultiVersus just couldn’t handle the project, for one reason or another.
A lot of speculation on the specifics of what went wrong, plenty of players looking for who to blame, but there will probably never be any reliable or concrete info on what exactly happened.
If you see a news article saying “X Sensational Thing has become a trend”, odds are is a gross exaggeration to the point of complete fabrication, and you fell for it.