Well, I've never even seen one played in my games, either, so yeah my three PCs were classing Fighter, Cleric, Wizard so I decided to go with Battle Master and Tempest domain.
Opportunities came up (like my cleric occasionally getting hit--though not often with his AC) but I still never used his Wrath of the Storm until late in the 4th session. I just never felt the need. The threat was minimal by then, I had plenty of HP, etc.
Even when my Fighter got missed (which happened often enough), I never bothered with Riposte, either. Again, just not necessary.
LOL I totally agree with War Magic! I loved it at 2nd level, but found the 6th level feature annoying. Of course, that happens a lot for me, so my PCs rarely make it past 5th level in any one class. I multiclass a lot.
I'm considering making a house rule and seeing if my DM will go with it to allow me to treat subclass feature levels as additional ASI/feats. I can see taking a feat or two more defining for my PC than most subclass features--but I worry that might be too powerful.
EDIT: I should add in all four sessions I never used Action Surge or Second Wind for my Fighter, either.
It wasn't that the encounters were "easy" or anything. My wizard and fighter each almost died in two separate encounters--I would have used them in the one where my fighter went down, but he went down before I could...