It's true that I don't know of any phone that allows that, or indeed of many point and cameras that allow that any more. Why you'd want to do that alludes me.

Photoshop Camera Raw allows the same sort of processing on JPGs as you can on RAW. I've only ever noticed a difference processing RAW vs JPG in my underwater shoots. That's due to the colour cast and even then, to be honest, the difference is so small I'm not sure it's even worth it.

I no longer shoot RAW on my DSLR topside as there's no discernible benefit. So why would I want to on a phone camera?

(We could do with the ability to save JPGs in maximum quality but that's a different argument).