I also think it works because the other shows are more serious. If they were all like this I don't think we'd be as high on Legends as we are. That's assuming they were all just as wacky and insane.Because after a brooding first season, the powers that be decided to lean into the fun parts of the show, that being the innate wackiness of superhero characters.
The lack of ability to access many of DC characters has led the writers to be creative as heck and it just works.
That said I do like it when Legends is more serious and I fear they're in danger of going to far in this direction.