I haven’t played FFXVI so I can’t speak on that, but you are right that if they can get a smooth, consistent 30fps it is much better. Hopefully they can achieve this. And 40fps would be fantastic, not sure why devs aren’t using it. It’s a good comprise if they can’t reach 60fps.
IGN just put out a couple videos about the game. 30fps may be all they can reasonably keep stable because the visuals look incredible. It will be a contender for most impressive visuals this year for sure.