In RPGs that give a wide build variety, I usually go wild and try to break the game.

In FF1, my white mage was my damage dealer. I try and build characters to work differently than intended, like if a character is designated a healer, I'd try and build them offensively instead. Or if a character is designated a damage dealer, I make them a healer for fun.

In terms of FFXIV, that's why I vastly prefer the HW era. We had so much build variety back then because potencies weren't that high, so crit wasn't a must. I had a lot of fun on full skill speed ninja. Was it optimal? No. Was it fun? It was to me.