I think that like most games which have a higher degree of mechanical complexity, it sings with system mastery. It does however (I think) move a lot of the choices away from builds and into moment-to-moment tactics?
Also, if you're a support-focused character the game will pretty much tell you via the subclass mechanics and ability choices. Some of the subclasses are far more clearly geared towards certain methods of play (control/ single target damage / area damage / boosting). However, there's multiple abilities across classes that attack and then boost an ally as well - including Recoveries.
I'm not sure if that answers your question directly? Honestly a problem my group has is that we don't have a "defender."
Also this is just my experience & etc. A guy just posted to reddit that he's done 50 sessions in teh game from playtest forward and his group is level 4 because they've been using it more as a vibe-based "talk to NPCs" and role-play game then a focus on its Victory granting frameworks and tactical combat.