Re: I wouldn't say it was ALL downhill.
Sadly, under BBC control, Peel was allocated a "producer" to keep him under control. He was never as innovative or interesting as during the few months he was broadcasting from offshore. Similarly, Kenny Everett was under the thumb of "Auntie", and was only allowed to really let rip when he was on the very early Capital Radio. Everett was an innovative broadcaster and very misunderstood.
British land-based pirates were good in the 70s and 80s, but lost their way when they all became "dance music" clones, financed by raves and drug dealing in the 90s. There are virtually no worthwhile pirates in the UK any more, with the exception of Radio Brittania broadcasting from the top of the pennines, and one or two others around the cities. London has nothing of any note these days, and persistent enforcement actions by OFCOM make most of the ones in the provinces sporadic at best.
Mainland Europe has a lot of pirate activity. France is getting lots on medium wave since their national broadcasters decided to close down there. The Netherlands has a healthy pirate scene, with some of the stations running many kilowatts. Germany suffers under Mutti Merkel and the kids are beginning to make their displeasure known, with many anti-immigrant stations popping up all over the country. Italy is the same chaotic mess that it always was, and Spain has lots of pirates. Greece is pretty active too.
The technology to build and operate clandestine broadcast stations has never been cheaper, and the power semiconductor devices available today are amazing - rugged, lots of gain, and pennies per Watt! Clandestine broadcasters use ever more complex means to conceal their studios and dissociate them from their unattended transmission sites. With some finance and Intelligence, a pirate station can evade the law for years. Their transmitter equipment will periodically be seized by the authorities, but there are seldom arrests and convictions for illicit broadcasting.