Let's redefine "damage taxes"

[Nutshell]

If a prange can be balanced with a melee then literally just do it without making up new roles.

That's literally all we need lol

The balance fix with BLM isn't to then ban it from playing with MCH and SAM, the point isn't more restrictions, it's less.

Well yeah of course they can just make everyone's damage the same and call it "balanced" but I personally like the idea of jobs that do more damage than others but at the cost of utility.
The paradoxical thing about my idea is that through those limitations you've mentioned we would actually see more party variety than we do now. All we have now is 2 melee, mrange, and prange for basically every party. With my idea each role could have choices in what kind of dps you'd want to play in each role. There could be parties of 3 pranged and 1 mranged and still get the party buff because those classes are from different roles.