Given Yoshis frequent opinion that jobs should be simple, and the difficulty should be from mechanics. I can sort of see the point your trying to make.
but I would also make the comment that if positionals are the only thing that keeps an encounter interesting then there's obviously a very big problem with encounter design as a whole.
I personally would like to see the balance changed a bit in terms of the combat : mechanics ratio. By making combat a bigger portion of the equation you can open up a lot of room to add some actual depth and interesting elements to jobs, which in turn would allow them to feel more rewarding to play..
But if hitting a positional for a staggering 2-3 potency per second increase is the most interesting thing about combat then there's obviously some much bigger issues. This is further demonstrated by the fact many of the people who want to keep positionals want to do so for the sole reason that they'd find combat "boring" without them.
They've had systems and ideas that have actually added depth and interest to combat.
The idea of battle regimens from 1.0 had a ton of potential.
The incapacitation system again had a ton of potential as you could actually change fights with it. break a bosses arm and he cant do that cleave... and thus will resort to other tactics...
Then there things like Crowd Control, Interupts, Kiting, Priority targets, etc. Even earlier dungeons had these things. Mobs that should be focussed such as those pesky bees that will final sting for example or mobs that had to be killed in a specific spot. where as now its just mindlessly aoe everything down and move along.
If you go back to 1.23 even the combat system was better and more dynamic. Rotations werent so strict and rigid but often required opportunity.. Even for tanks where there was an element of skill involved in timing that moment where you could duck behind a boss and start your dps combo without moving or turning them and getting everyone else killed..
Where now rotations are static dull and boring. they never really change much.. If it wasn't for the devs blocking queues on macros players would literally macro entire rotations because every boss is the same. Which is why people often refer to muscle memory because all you ever do is the same rotation over and over and over..
But when positionals are literally the most interesting thing about combat. it says alot about the combat...
They really do need to add some fun, interesting and actual rewarding elements to combat. Even if that means making encounters mechanically simpler. If the jobs are more fun and engaging to play I think thats a decent trade off and would allow for a decent skill ceiling.