as well as the Battle of the Beanfield in 1985 there were riot situations at raves which got shut down in the early 1990s as well, same sort of stuff, rigs getting trashed, people on both sides being injured.
its not so much things have necessarily got worse, its just that there has been no real progress since the early 1990s.
BTW the people in the original video were a bunch of middle class young tory types [1] running parties with a substantial entry charge and their own security and dealing networks (led to some nasty turf wars!)
they tried lobbying Parliament but were told the govt would not negotiate with lawbreakers (thatcho was PM then!)
They eventually all backed and decided to hold licensed parties within the framework of the market (opening hours were extended and all-nighters permitted around 1991) – which they did until the tories shut those down as well because of the drugs.
There was always a free festival movement due to hippies / crusties / punks and when they picked up on the rave scene around 1991/2 free parties were started as a response to this.
[1] And I would not be surprised if one David Cameron may have been to a couple!