I don't agree with Wayward / Unreal World and the whole point you make.
They are not one bit similar. In fact, I believe the notion of endgame is completely misplaced in Unreal World (or open-world, survival games in general), at least if you do not play out this weird concession to standard roguelike (level-up) play in the form of permanent repetition of game courses with a min-maxed Kaumo (and don't play it like DF adventure mode). In fact, I am pretty sure most (military) "endgame" chars are not even more successful in the survival aspect of the game measured in time, they just kill a lot to feel as the ultimate survivor.
Of course the open-world gameplay once you made it past the initial obstacles is more boring / philosophical / self-imposed challenge. But this is much the same with all open-world games. (DF endgame difficulty is the heroic fight against FPS-death and otherwise completely self-imposed as well). URW lets you play in the open world, not requiring an endgame / rescue the world whatever moment - and an arrow in the eye will remain deadly to you, whatever skills, equipment etc. you have. As opposed to that Wayward frantically moves towards an endgame which simply does not happen, but it does not allow for open world gameplay (other than permanent repairs).