Many municipalities have laws against engine breaking because of how much noise pollution it causes, so I don't think your example works they way you expect. Especially considering this would cause that noise pollution for 10s of millions of people.

Not even remotely correct. They flew supersonic aircraft over Oklhahoma City a thousand times and basically drove the city insane and had to cut testing short when it was obviously untenable to regularly Sonic Boom half a million people for commercial aviation, let alone every large city in America.

https://en.wikipedia.org/wiki/Oklahoma_City_sonic_boom_tests

If I'm doing my calculations correct, their targeted sound pressure levels of 50-100 pascal is equivalent to 127-133 decibels, which is over the threshold of discomfort for most, and getting close to the threshold of pain.

This seems bit excessive, Concorde booms were purportedly about 105-110 dB on the ground when cruising at altitude (around 60 000 ft).

I've personally only experienced sonic booms from MiG-21s. They are not painfully loud, but surely startling. They are very deep and make the windows rattle.

My childhood home was in the flight path for NASA when they were given the Blackbird after it's official retirement. We also routinely had fire-retardant bombers flying eye level close enough you could read the tail numbers off with a naked eye (we were on the side of a mountain, bombers flew down the valley).

Point is: the Blackbird, flying at altitude, sounded like a tree fell on the house . Big crash/thud suddenly. The bombers, though loud, were a steady build up until they passed, then quietly faded away. The Blackbird, I literally remember leaving the house to make sure there wasn't a hole in the wall or roof.

Blackbird was a beast, literally the fastest plane out there and it never really slowed down. Compare shuttle, which came in much faster but few ever complained about its boom.

> their targeted sound pressure levels of 50-100 pascal is equivalent to 127-133 decibels

At what distance from the plane?

It's no myth. I'm old enough to remember sonic booms as a regular occurrence. We were used to them but they were definitely louder than a jake brake and they disturbed a much larger area.