There is something to be said for a more compact resort even it it is more urban, with Disneyland perhaps a reasonable comparison as any third park would certainly require some travel from the centre of the current resort.
I do think it is hard for Universal to recreate the resort experience of WDW, though. Walt set up the resort well, with lakes and forests that do make it feel like a self-contained resort destination in addition to being a collection of theme parks and hotels. Sure you can take an Uber anywhere and you're not stuck at WDW, but WDW can also provide you the experience of feeling in your own little vacation kingdom away from the outside world if that's what you want. That's just harder for Universal to recreate, for example with Volcano Bay wedged right up against the highway and expansion requiring some travel along normal city roads.
It's not fatal here nor would it be if Disneyland chooses to build a third park. It is a disadvantage, though.
