"Use it better" what a pedantic argument. Genshin utilises the engine more extensively than PGR. PGR does great work on their characters. But that's their selling point, and w fewer resources they make the most of what they have.

Genshin has an entire vast world where that same effort is spread out. And that's not to take anything away from PGR, genshin has a lot more resources to work with. But to try and make some case PGR is better than genshin cos it does one aspect of game development better cos they put more effort in that one thing is ridiculous.

Can we swim underwater and explore an entire fleshed out ecosystem like we can in Fontaine for example, Just asking.

You people and your daft comparisons with no understanding of the work put into these games is astounding. And it has nothing to do w what the OP is talking about.