Oh, I remember how slow was FFXIV on my powerful (for that moment) gaming setup. Their performance optimization suck.
It doesn’t matter how beautiful your engine is if only chosen ones can run it max settings.
If we speak about functionality, then UE4 has everything. Hair? Well if you really want it you can hire a team and make your own UE4-based solution. And it will cost less than SE spent for their engine.
Overall, nothing impressive in that engine.