That kind of free, I don't mind. PSO2 has something similar, where you don't need to buy anything to complete the story mode or provided missions. Usually players spend money for the sake of fashion than power.
SEGA's biggest mobile game earner, Project Sekai Colourful Stage! feat. Hatsune Miku, also like that, most purchase was more fashion.
They don't even add any new characters, all characters are the same since the beginning of the game.

So doesn't that mean SEGA is generally still good in term of F2P?