The video was just to show what the engine can do, think of it more like a tech demo (though according to the dev, the project's still in development). The sameness you see in RPGM games isn't the engine’s fault, it's just devs being lazy or lacking the skills.
It's kinda the same thing as how, these days, when we see UE5 in a new game, we instantly out in a cold sweat, but that's not 'cause UE5 is bad, it's the tech team that doesn't know how to, doesn't want to, and won't bother learning how to use it properly.
ARC Raiders, which came out recently, once again proved that a UE5 game can run at 4K 60+ FPS with no stutters or upscalers.