complicated incoming
"i agree that most EDM is bad, but some of the best music of the last 30 years is EDM."
because this generic statement applies to just about anything; go get Janis Joplin's albums, half the songs are crap filler. same for the stones, deep purple .. you name it. the vast majority of artists produce a few catchy songs and much worthless filler.
keeping that in mind ..
first off, i dislike the term Electronic Dance Music; i prefer, if we need to use a blanket term, "Techno", short for "music made with technology". Of which techno is a subgenre. (because we like it complicated)
EDM could also refer to many new wave songs played with synths; but Techno is only songs which are made with prerecorded sounds - no live performances.
(you can play a riff live, then sequence it - it still applies)
The key here is REPETITION. Repetition has been a "thing" since medieval music, where it was called "ostinato"
https://en.wikipedia.org/wiki/Ostinato
Monks found that repeating things "stubbornly" had a trippy effect which they liked, as they made music to "be closer to God", or, in plainspeek, to trip out - which is why pre-electronica trance also shares most of the characteristics of techno.
Incidentally, legend has it that the first wave of proper techno, was inspired by the trance played on the hippy beaches of Goa, back in the 80s and 90s a popular stoner holiday destination.
But i'll skip the history;
essentially, techno is designed to be that way, for the trance-like effect it has on the body, and mind you, i mean primarily
on the body, not on the mind. Repetition has a physiological effect that "normal" music does not have; while normal music is mentally stimulating, techno is soporific - hypnotic, trancelike, calming.
Now, you'd think that "menatlly stimulating" is certainly the preferable of the two; but not quite.
Techno in general takes longer to have an effect; i too thought that techno was disgusting "non-music", until i was forced to go to sleep one day while it was playing. My brain tuned out a portion of itself, and my body relaxed. I understand this sounds gay AF but that's how intense the experience is.
Now, i won't say all techno is good; *most* music made past the mid 90s is crap, since it was made to make money and there was no spiritual inspiration in it. But much music before that period was really something else.
Of course there is the discussion about drugs. Techno and drugs - if you have already been initiated to techno - beats rock and drugs any day. You can have your grateful dead trip, techno just smashes it. The trance-like physical phenomenon of techno enhances the physical phenomenon of drugs .. while rock and trip might make you think weirder things, techno and trip makes you FEEL better.
Dance, and Disco before, were not different. It's about having a body experience, not a mind experience.
Also, there is the fact that techno *sounds* better; due to not having any real instruments, who need recording on physical medium (still using analog tape back then), there's air between microphone and amp, electrical noise, etc, techno sounds crispier, with far stronger and clearer lower frequencies.
When you go to a concert, it's loud. But when you go to a disco (where the speakers are much closer to you) you can feel the vibrations shake your ass; and your guts. You can literally feel the
vibrations make your interiors go
wobble.
Ok, lets move on.
Techno in general is about the quality of sounds. Not just as i described now, but also to "this sound sounds great". It's a distant child of "Rumorismo"
https://en.wikipedia.org/wiki/Noise_music , and just like, when you were younger, the lightsaber made that awesome sounds, and so did the TIE fighter, techno is all about finding sounds that sound awesome.
If you will, this "sound palette" takes the role that arrangements had in classic music.
I'm afraid that, if you don't have experienced techno by now, it's too late. It was a great cultural movement, which sadly now has been eaten by the big labels.