Mannahnin
Scion of Murgen (He/Him)
I appreciate your openness to some nuance here.I've can't really conceive of that happening. The feats are pretty general use. However, in that very, very corner case scenario, at worst they would be equal.
It's harder to rate entire classes against one another since they have so many varying abilities. Identical fighters with only one having a feat is not the same as Paladin vs. Fighter mixed in with how rests are done. One is basic math and the other is calculus.
Another thing to consider is that when comparing whole classes, much of that comparison is going to be subjective. Do you like superiority dice more than smite for example.

Well, now we're getting into fairly philosophic territory. Personally I tend to believe that if a tree falls in the woods and there's no one around to hear it, yes, it still makes a sound. But some realities are inherently subjective and internal and not as hard and objective as the measurable decibels of a falling tree.A of these things you bring up are what causes the misperceptions to occur and are the reason that perception is very often greater than reality. They do not alter what reality is, though.
Which character classes or individual characters are more powerful than others in a game which has flexible rules and implementations thereof, which takes idiosyncratic expression at tens or hundreds of thousands of different tables, each of which creates different conditions under which each class would or could be measured, is a much less concrete and observable thing.
In the context of my game the way I run it, a given character may be significantly, observably, obviously-in-the-view-of-all-participants, weaker or stronger than they would be in your game the way you run it.
I think "which character class is better or stronger" is often a matter of opinion dependent on context, more akin to "which food tastes better" or "which movie is more artistically satisfying" than it is to something like "which ingot of iron is heavier".