If color identity were abolished, it would allow me to play
Ramos, Dragon Engine in my
Reyhan, Last of the Abzan deck. Sure, that could be fun.
I am not saying that there wouldn't be fun or quirky things we could do.
But I am saying that I would play
Anguished Unmaking and countermagic] in almost every deck. I am saying that I would play Cyclonic Rift in
Mina and Denn, Wildborn. I am saying that my mono blue and mono black decks will play green ramp spells.
Kozilek, the Great Distortion could run green ramp and white wraths and blue card draw.
Color identity does a lot of work for the format. The most important is that it gives you downsides to building around a specific commander. I am choosing a powerful general but the tradeoff is that I am limited in what I can play in it.
Sure, I can play 5 color mill right now, but Golos is not really helping that strategy. So instead I play Phenax and I am limited to UB cards.
Most people see this as a positive about Commander. These kinds of restrictions really make deckbuilding creative.
I can see the idea that
Jeskai Ascendancy would be fun in
Phenax, God of Deception. But, the problem is less so the fun and quirky things, and more that my deck would also shore up all its weaknesses by playing white removal spells, and that my deck could play some very powerful cards like
Gaea's Cradle,
Dockside Extortionist and
Teferi's Protection. There are a lot of powerful cards in magic and opening them all up to every general will cause a lot of decks to play the same powerful cards. It would make the format more repetitive, less creative, and would be an all around negative.
The format is the biggest and most popular format aside from 'kitchen table'. The real answer is that abolishing the CI rule would risk destroying the format, and for that reason they should never touch the rule.
If people want to build around a general but not be limited by flavour/CI, then the better solution is to make a new format. And you can get rid of CI, remove the 100 card limit, and make planeswalkers generals, and change life totals, and make a ban list. There is probably room for such a format.
I think the cEDH community would enjoy it, since so many decks are 4/5 colors anyway and often the generals are just there for CI. Instead of playing
Vial Smasher the Fierce, you could partner your
Thrasios, Triton Hero with
Kodama of the East Tree and still play 4 colors.