That "just play whatever is fun, who cares if it sucks!" mindset really only works in games that are largely solo experiences. In something like Black Desert Online, where 99% of the content is solo-oriented, having a weaker or less efficient class doesn't meaningfully impact anyone else. If your class underperforms, you're mostly just affecting your own progression, so the game can get away with shitty balance.
But in a game like Monsters and Memories, which is built around group-centric gameplay, that dynamic changes completely. Your class choice doesn't just affect you, it'll directly impact the efficiency, success, and overall experience of everyone you're playing with. When players are investing significant time into forming groups, traveling, and tackling content together, they're naturally going to care about optimization to some degree. Not necessarily in a hardcore, min/max-at-all-costs way, but enough to avoid situations where someone's class choice becomes a liability.
That's where class balance becomes far more important. If certain classes are noticeably weaker, less useful, or bring less to a group, players will inevitably gravitate toward stronger options. Or worse, start excluding others. That undermines the whole "play what you enjoy" philosophy, because social pressure and group expectations take over. So while the idea of total freedom in class choice sounds great on paper, it only really works if the game's structure supports it. In a group-focused MMO, balance isn't just a "nice-to-have" it's foundational to making sure players can actually play what they want without feeling like they're holding everyone else back.