This is some revisionist romanticism. I won't speak for all fighting games, but going just off the starting casts of prior Street Fighter games:
Street Fighter II: 8
Street Fighter III: 11
Street Fighter IV: 25
Street Fighter V: 16
Street Fighter VI: 18
Except for IV, which yes does have an additional 7 characters, VI has the biggest starting cast of an SF game yet. Unless you've been dissatisfied with all these games at launch in which I'm sorry for getting ahead of myself.
The nickle and diming is kind of lame, yeah, but like Blizzard used to be, I can forgive it because the game is actually fun and you don't have to pay to win.