I'm sure they still exist here, but the economic realities make it challenging in my area (NYC)... even smaller events must be totally oversold, in order for the promoters to not go broke. So it's hard to find room to dance, and there's lots of people talking loudly everywhere, etc. And the headliners often start their sets at an absurdly late hour.

There are still some underground parties, but most of the ones I've been to in modern times have been a bit "off". In some cases the promoters are attempting to recreate a 90s/early'00s vibe, but they aren't old enough to have actually experienced one, so they're just basing it off the ridiculous exaggerated thing they saw in some movie. They'll overspend on decorations but underspend on DJs. And they'll do things like wait to send out the address of the "super secret underground venue" until the day of the event, but then it turns out to be some totally normal event space that anyone can rent.

Probably there are still some actual unlicensed/renegade parties somewhere here but I haven't found them. The only ones I have come across have been a bit of a different scene, more like experimental electronic that doesn't lend itself to dancing, no real overlap with the genres that were played at raves.

edit to add: no idea why you're getting downvoted above. fwiw your comment about PLUR totally aligns with what I've heard from others in Europe.