No thanks;

It’s not the same, but they did have something kinda-sorta like this with optional abilities you could get in 2.x.

(Aka play warrior to get the provoke skill for tanks)

It just resulted in “you have to get all the things”, and wasn’t really designed for experimentation.

Bottom line in FF, if I get into a dungeon with any tank, I need to expect they can do xyz, and not have it be a mystery whether they can do xy or z.

Similarly they allowed putting points into attributes, but it boiled down to “just do this or be suboptimal”, and they had materia for similar purposes. It’s all been removed, mostly.