It's the best overall firework show in the country - it certainly isn't the best firework display. Jubilee seem to have less and less influence year on year also, with other areas utilising their previous budget - e.g. the drone display pre-show last year and the flame & CO2 effects of the years prior.
Ultimately the park convey their idea for the show to the various contractors and then they all work together to produce something that comes within budget and is on theme.
To be fair to Alton Towers. Their end of season show has never just been about fireworks. They were broadining the horizon and raising the bar in what is possible in a multimedia entertainment display, 30 years ago. Something which they still do to this day.
The drones are relatively cheap and easy to implement into a display. Equipment is rented and operated by professionals, like your lights and PA would be.
Maybe the budget has been cut in recent years, show elements such as the wickerman flames in 2018 and the enterprise like rig in 2015, would cost far more to implement than drones so I would suggest the opposite may have happened. Where less money is going on non perishable show elements in the last few years.
Back in the later Tussauds days. 2003 to 2004 sort of time, pyrotechnics had a £30,000 budget per show. Flame machines, lighting, PA and all the other show elements were ontop of that cost. All the non perishable equipment basically.
I remeber the one year, it may have just been after the shows restarted from the Roper drama, the audio setup was arranged into a cardio array setup. In simple terms, speakers are arranged in such a way that the lawn volume and decibels are very loud. Speakers are arranged in such a way that the physical wavelengths cancel each other out, at a pre dermined point (usually just off site or near the edge of the site). Ensuring off site audio levels are minimal to non existent, while maintaining very loud audio within the arena so to speak.
Very clever stuff. The same will happen if you get two waves at the right point in your bath, you can't argue with physics. This lovely technology is just recently making it's way to consumers in the form of noise canceling headphones.
Turning the volume down is simply not an option. It never has been. Hence the development of this tech.