But, here's the thing. If uniqueness and distinction are important to you (and I largely agree actually, I'm a big believer in class niche), that's fine. But, to claim that classes feel the same in 4e because they have the same power structure, but, don't feel the same in other editions, despite the classes being built on the same power structure, it gets rather confusing.
Because you are comparing apples to oranges. Having different armor proficiencies isn't a difference in structure of the class. Everyone has armor proficiencies and they get them at the same time. They may have different proficiencies, but, that's not a structural change. Clerics may have a different spell list than wizards, but, structurally, they function exactly the same way - choose your spells for the day from a list and that's what you have. Having a longer or shorter list of choices isn't a structural difference.
In 4e, I could create two characters with the same class that share pretty much nothing. Completely different abilities and powers. Completely different play as well. You couldn't possible match the customization of a 4e class with any other edition.
So, claims about "uniqueness" seem like such a bizarre criticism. Every fighter in 5e is pretty much the same. At least until 3rd level. And, even then, there isn't a huge difference. And two fighters with the same subclass are going to be virtually identical in play. And, if we go back to AD&D, it's even less unique. Two fighters are going to be nearly identical - the only real difference might be in stats.
Like I said, claiming uniqueness as a tradition in D&D seems like a really strange one to me.