Bonfire is a huge thing here (Sussex). Almost every town and lots of villages have their own "bonfire society" and put on an event where the they have costumed processions, followed by a professional standard firework display. The bonfire season starts on the 3rd weekend in September and ends on the 3rd weekend in November.
All the societies go to each others events, usually by coach, so you can expect loud fireworks late into the night almost any weekend during the season. People let off their own fireworks on the way home after being dropped off by coach.
A lot of these people have done pyrotechnic training, so they can buy fireworks categorised for professional use only. Anyone who fancies having a professional firework display for their wedding reception/birthday/anniversary can usually find someone who'll put it on for them at a fraction of the cost a company would charge, so all sorts of biggish displays go on at all sorts of odd times.
In Lewes, where they have the biggest event (biggest firework event in Britain), they have fireworks the night before 5th November, fire off a few big maroons at 6 or 7 am am, fireworks throughout the day and night and then let off any they've got left the following day.
When I say big fireworks, they are so big that at my friend's house, they make the windows rattle and you can feel the boom through the floorboards. You can't just sit in and watch tv, you'd need headphones to hear it.
They also lockdown the town from 4pm - 2am, so if you haven't got home from work by 4, you can't get home at all. The trains don't stop from midday to the following morning, to try and keep the crowd numbers down. This also means residents can't go out for the evening and get away from it.
When they have the local event near us, we go away in our motorhome for the night, because the noise scares the dog and I can't bear her barking non-stop for hours on end.
I feel really sorry for anyone who hates it, it's so hard to avoid. A change in the law for professional demonstrations only wouldn't change that. I also think the mad buggers would just start making their own (which is surprisingly easy), which would probably be even more dangerous.
The police do nothing to enforce the rules about letting off fireworks in the street, even outside of events, or the rules about no fireworks between midnight and 7.00 am. I've seen quite young kids (under 10) letting off really big bangers or agricultural rookscarers in the street within 10 yards of a plod, and the plod just watched.
Unsurprisingly, there's a high level of deafness and a lot of people missing bits of fingers!