My observation is that we were just bored a lot. It has been a long time since young people have been as bored as we were back then.
Totally different decade, but my 90s high school experience was very similar to the movie Dazed and Confused. It’s odd how similar those experiences were versus what has come with the tech disruption of youth.
Eh, I think it depends more on the location, than anything else. I grew up rural, we did basically exactly the same thing as you described, hosting raves in the forest, beaches and what not until we get word that police was on it's way (tiny place, everyone knew everyone, police coming was big news as we didn't have local police).
We did have cellphones, the internet and more, but still, we were bored and dancing all night in a forest was the most fun we could have :) This was between around 2008-2011 sometime.
These still exist! Look for events promoted as such, or look for smaller local events for the genres you're interested in - the latter might not ban phones, sure, but the vibe is still what you're seeking. Nobody's recording you.