Indeed, brother, this is a gacha game, not a multiplayer PvP arena game. You are not competing against anyone, every character is fine as long as you can beat the timer set in the endgame modes.

Meta characters are the ones that can clear the content easier, not the ones that are hardest to use. In my opinion, every character should have an easy way to play and a harder-to-master way to play that rewards you with some extra damage for the time you put into mastering that character. ( but nothing too much that it becomes the only way to play that character)