Assuming Hellblade II has an actually great 30 fps implementation (a la FF XVI), the situation should be pretty different from Dragon's Dogma 2 and its piss poor fluctuating 30 fps target (and broken checkerboard rendering atm, etc).
It's pretty unlikely we'll see many UE5 titles targeting 60 fps at viable resolutions this gen, unfortunately... Although they could (should) implement 40 fps / 120Hz modes wherever possible tbh.
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.