I fall somewhere in the midfle in this way...Yeah, well, you know, that's just like, uh, your opinion, man.
So the disconnect that keeps happening in this thread, as in so many others (IMO) is that people just play differently and like different things. I'm using this particular quote as a starting point, acknowledging that you correctly stated "I think[.]"
Some individuals use 5e in a very OSR/1e way, where classes have a strong identity. Where fluff and mechanics are necessarily intertwined.
Some individuals do not- where mechanics are, well, pretty much completely separate from mechanics, and you can re-imagine the mechanics with almost any sort of flavor. Allowing you (especially with MC'ing) to build concepts from the various abilities.
And some people (most?) are somewhere in between.
That's all find and good, but there is no foolish, or better, just ... different playstyles that appeal to different people, or even to the same people at different times.
It's like saying that it's foolish to play with a grid, or with ToTM; neither is foolish, or not foolish, just different ways of choosing to play. And there are ways that you can play different styles well, or poorly. I mean, there are certain techniques that are universal, like good communication, but otherwise ...
And that's why we get to the bizarre arguments. People will advocate very strongly for their own style of play, while other styles of play seem, well, strange to them (or even foolish); but it really is just a matter of preference. I know, for example, that a person can be the most amazing and wonderful tactical DM with intricate combats that have been mapped out carefully ... but I won't have a good time, because that's not what I'm looking for; it doesn't mean s/he's a bad DM, or that it's a bad way to play D&D, just not my preference. Same here- some people like a stronger class identity, some people like intertwined fluff & mechanics, and some don't.
I feel some classes have fluff tied to mechanics and others do not.
There is no explicit statement in the PHB that says all classes are the same, so i see them as different.
Some classes come with baggage, some dont. Not all come with the same size baggage.
That will mean certain types of players, knowing that about my games, will tend to certain classes over others while other types might skew the other way.
I am fine with that. It is not my goal to dilute my campaign to the LCD of every class having all the same "flavors".
If you want to play a character with ties inside the class to other NPCs that really matter - cleric, warlock and others and some sub-classes will fit your bill as far as that goes.
If you want less of that there are plenty of other choices too. Fighter doesnt come with that kind of ties, neither does rogue or sorcerer. Others may fit that bill and sub-classes.
Backgrounds, races setting appropriate backstories can also tweak this dial but within parameters that make sense.
As i have said, i would draw the line at taking a class with baggage and just fluffing away the baggage as it creates a pretty big glaring break in the world works this way kind of sense.
So, i am likely not gonna appeal to certain player agency dialed to 11 types and thats just fine with me.
All i know is, the players i have had play the baggage classes/concepts have loved it and others who avoided them under other gms have tried it under me after seeing it in play.
So, i must be keeping my slavering under control.