I’m hearing a lot of “has to” with respect to fighters, each of which has a steep opportunity cost. To do his job, he “has to” take Sentinel. He “needs” specific magical items to increase his speed, to fly, to detect invisible, to damage opponents that are resistant to non-magical damage (at least two, for melee and ranged), which he spends his limited attunement slots on. If he wants to contribute outside combat, he needs to spend feats. None of this is easy to respec on days when there are fewer combats.