In reply to Removed User:
This is a subject I have been thinking about lately as a biker and climber getting back out again after covid/winter.
There is existing legislation about noise emissions from bikes. It is very specific, a maximum of X db at 3 ft at 3000 rpm or something like that. The problem is just that it is not enforced.
Manufacturers get around the rules by selling exhausts with a removable sound deadening baffle. The baffle reduces the noise to a legal level and supposedly you should only remove the baffle on the track as it makes it illegal for road use. Of course a lot of people take it out and only put it back in for the MOT.
I personally don't believe "loud pipes save lives" - on this basis any cyclist in the city should have a siren! Some recent reasonable looking academic research backs this up: https://www.motorbiscuit.com/new-study-confirms-loud-pipes-save-lives-is-sa...
I think the loud bikes (and cars too) is primarily an antisocial thing (i.e. my enjoyment of the noise is more important than others dislike of it). I think it is also a community driven thing, if you are in a group that does it, or watch a lot of youtube videos of people doing it, you are more likely to want to do it too. As we have seen with all the political stuff lately, the power of groupthink is very strong, there is the element of wanting to fit in and and also the self justification, where if you and others around you justify a behaviour enough then it can become normalised.
I think the solution is really easy - just enforce existing rules. However, with all such things, this will need political will. If you feel strongly about it, contact your local representative and enough people do this it will become a policing priority. Local to me there is a road where young people rent Lamborghinis and race up and down at night, enough people complained so the police cracked down a bit and it is much better now.