It's a great question in a great forum.
I'll limit myself to the question at hand.
Low SPL firecrackers that use only regulated chemicals, made in non-exploitative factories that pay better wages.
That's the solution.
I come from a part of the country that is a virtual stone's throw away from the big makers. I can tell you there was literally a loudness war going on between the manufacturers in the famous town in the early 1990s. The war was in just one segment - called the Laskhmi vedi, aka sutli bomb/russi bomb. The top manufacturers kept trying longer jute wound tighter with the same ammo, while the competitors just went for more ammo in a thinner wound jute.
By 2000, the loudness war had migrated to pyro, and these same manufacturers worked towards more bang and brightness.
They all just ended up overdoing it, their competing products just flooded the markets, and here were with people in 2021 fighting an ideological battle.
Just tighter regulations on what they can use and how much they can use will give a better Diwali for the entire country. But the industry is highly unregulated and too powerful.
Having said that, a majority of revellers use only sparkles of phuljadi type things, which also need regulations, but they don't disturb anyone overtly. It is these 'bombs' that cause the real problem. And the 'sara vedi', the threaded terror - measured in 'wallah' - 500wallah, 1000wallah, 10,000wallah... meaning small firecrackers measured in multiples. The sustained noise they make are a pain for anyone.
PS: It is only the very sensitive of the ears, oldies, and pet parents who used to complain back in the 1990s too... Today, it is the same demographic that is complaining. Only, the SPLs are way off the charts. I'd venture an uneducated guess to say that in the Lakshmi bomb loudness war days, it might have been a race to 90-95 dB. Today's firecrackers easily hit 140+
Aside: Did you know a box of matches finally is going to become 2 rupees soon after some 20 years? Same industry, which has faced this social media stigmatisation without any genuine regulation.