Got the expansions for the base game years later to work on my living dex and had a surprisingly good time with the DLC. The secret sauce here is that the whole island is a wild area. I think this represents an important step for the franchise that wasn't talked about at the time because in the end I also agree that this should have been in the base game. As we can also see from Scarlet/Violet, the concept of gaining a legendary at the beginning and growing alongside it is a formula that makes you feel much more attached to the mon in the end and IMO makes for a better overall experience. It was just a bit too short in the end.