"Turn Based Combat wouldn't work with photo-realistic graphics due to it breaking immersion."
Yes just like how it broke the immersion in every other Final Fantasy game that has it right?
Oh wait, it didn't so that excuse is completely bullshit.
"Final Fantasy VII Remake would not have sold nearly as well if it retained turn-based combat."
That is a fat sack of crap and you damn well know it. Final Fantasy VII Remake sold as well as it did, BECAUSE it is Final Fantasy VII, it has fuck all to do with the weather the gameplay was action or turn based. It wouldn't have mattered what gameplay they put in that shit, it STILL would have sold like fucking hot cakes.
There's NO good reason whatsoever that mainline Final Fantasy games can't still be turn based.