It could be that I'm just not trained enough on other genres, but I'd argue that the differences are generally bigger, and the genres being much more numerous makes perfect sense. Because "Electronic [Dance] Music" just means that electronic instruments were used more prominently than any acoustic instruments. That says extremely little about the music. Whereas Jazz means something very specific.
To name three "Electronic Music" genres, if you compare Hardstyle vs UK Dubstep vs Tropical House, I'd say the difference is much bigger between any pair than "Nu Jazz" vs "New Orleans Jazz".
You can conveniently grow an opinion on this here: https://everynoise.com/
There are genres of electronic music that are like metal (very uptempo, in-your-face, maximalist) and ones that are like jazz (smooth, free-flowing, open, not maximalist). Both being very common and huge subgenres. But where's the jazz that sounds like metal or the metal that sounds like jazz? They might exist, but would be incredibly niche.
Besides, people nitpicking over subgenres exists in many genres. Metal (or really "Music featuring heavy electric guitars") is famous for it. But in both it's only a small minority of people who spends their time doing this, mostly teens or people online, very rarely people actually visiting and enjoying shows.
"Jazz" should be compared to "Techno". And people definitely go to "Techno" festivals, even though you can further divide it into "Hard techno", "Industrial techno" and so on.
