I'm not convinced that it's a question of ambition. Recent FFs just seems like overblown, poorly-managed vanity projects. They're no longer doing groundbreaking, trend-setting games. They're just bringing in directors to come in and design whatever they think is cool, throw "innovation" at a wall and hope it sticks, and then just scrap and start over again next time.
- FFX took the battle system back to the NES days by dropping ATB, but it worked well enough. The sphere grid was a good idea, but too easy to max and make ridiculously OP characters. But the characters were awful and designs were repulsive (thanks Nomura). The story was a decent 3 hour story stretched to 30 and soap opera'd like no one's business.
- FFXII was an improvement in every way. It seemed like Final Fantasy was back on track. Ivalice has a totally different feel to it than other Final Fantasy experiences, but in a good way. The characters took a back seat to story and lore, but that's fine with me. Lord of the Rings did it too and I have no complaints.
- FFXIII was back to being a terrible story with awful characters and terrible designs. Then the paradigm system streamlined and watered a 20 year old job system down to 6 classes that all perform 1 very specific task. There's no complexity or nuances to it. It's simple enough to win the game with auto-battle. The game is just a bad TV show with a brain-dead battle system.
- FFXV seems to be Xenoblade with a more powerful engine and Nomura's trademark awful character designs. We'll see how it goes, I guess. Bishounen Fantasy may turn out OK, 10 years and 100 million dollars into development.
I don't know why Square Enix has gone from setting industry standards to being obsessed with glorified tech demos. FFIV was one of the most influential RPGs ever made. It was years ahead of its time and a game changer. Almost every JRPG since has been influenced in some way by it. But now it's been 5 years since FFXIII and the only game it influenced was FFXIII-2. Sakaguchi may have sold his soul with Spirits Within, but the games just haven't been the same without him and Uematsu.
The best Final Fantasy games in the last 10 years were The Last Story and Bravely Default.