I could never get into 12. It had a weird hybrid system that didn't click for me.. it also played like a offline MMO.. not my cup of tea. The characters were also a bit.. eh.
Onto XIII yeah some are insufferable like happy go-getter Vanille, but once you kinda clock out of their weird quirks and awkward dialogue, that probably only work on Japanese dialect and customs its not that bad. Like there was nothing like that laughing Tidus scene in that game lol. But yeah it was the switching back and fourth between specs, balancing offense and defense and working with timing. And getting that stagger for big damage. A mechanic that was added on FF7R.
I don't know not for everyone. I enjoyed it enough to complete and that makes it pretty good imo.