I think what OP wanted to point out is:

The center of the universe is the raid.

If something upsets the raid's dynamics between jobs, the game falls apart. Same thing with gears.

What I think the OP dreams of is the separation of raid abilities and open world abilities, like a section of Raid Skills that can only be used in Raids and an Open World Skills that can only be used in the Open World. The Raid Skills will be balanced around Raids while Open World Skills can go crazy with what it does. Like PVP with their PVP skills.

Balancing the classes are centered around the raids. That's why BRDs and MCHs weren't taken into consideration before Alex Savage came out. Same with AST and DRK.

OP's suggestion is a little bit off mark because the class/job system is no longer relevant. But hey, we can all dream can't we?