The Final Fantasy and Kingdom Hearts games are some of the most ambitious creative projects in any medium in the world. Arguing against that is comedic folly at best. They are by far the most ambitious in their genre, but that much is almost too obvious to be worth stating. lol
That said, yes, the ambition can create flaws like XIV 1.0's failure, which was miraculously rectified by the amazing 2.0. FFXIII (which I argue ceaselessly is a great game) has flaws in its design as well. As long as the company is being functional and not stepping on their talent (like they did to Versus XIII for ages), then their ambition, resources, talent monopoly, and high level of freedom will continue to create the best and most ambitious projects we play.
It's also worth noting that SE's huge KH and FF ambition doesn't seem to go into their FF sequels (not true for KH, which retains its ambition). FFXV-2 (if it does indeed happen) and FF Type-1 are almost guaranteed to be departures from the sequelisation problems seen with X-2 and to a lesser extent XIII-2/LR.
FFXV is looking like the very best of ambition. c: