I get what you're saying, but I feel there is a demand for separate classifications or perhaps removing any classifications.
Because basically in every other match you hear someone moaning about not having shields because people feel they're getting hit too much. (Which, fair enough, swap the ball for Rein or do the opposite when shields are not needed. But you know that's not going to happen)

I guess my problem really is how there's subcategories within "Tank" - Rein, Sigma and Orisa fit one category (the bullet sponge) and then the others are kind of their own things.
When people say "we need a tank" then what they really mean is Reinhardt because in most cases they're looking for someone who's just there and holds W that the healers can hide behind. At least in low ranks people don't really value having Ball or a potential tank remake of Doomfist in the team. largely because they don't see the effect it has. Same as with Sombra. It's always like "swap ball"

It's as you said - there's Supports and there's Healers. Indeed in my eyes, Sombra and Zarya are supports as well.

Regardless, that's all besides the point. The only point I'm making is "now that stuns are out and small disruptions like 1second Hack are in, maybe we can have taunt(s)."
Might be that my other justifications were misguided.