With all three characters i had till now one of my i thoughts was “but how good would the other sub-class facilitate this skill” and never thought “what other skills would this sub-class work with”. So for me the locked in subclass feels like i have to make another character to try new things. It feels a bit frustrating having to level the same character again to try out.
It wouldn’t be so bad if the campaign wasn’t such a slog after you’ve done it a few times. It almost always is in ARPGs. At least Diablo 3 lets you skip the entire thing and level up without doing it once you’ve done it once. I know this one does too for part of it, but you lose a lot when you do it since some things are only unlocked from doing the campaign.