Massively reducing car usage is a much better solution with much more wide-spread benefits.

That as well. But it does feel very wrong that combustion engine users can emit huge amounts of noise and pollution while sitting in sound proof, HEPA filtered boxes.

The horn on automobiles should be mounted inside the cabin. They can make it as loud as they need to make it, but the person who hears it the loudest should be the driver.

I've often thought this should apply to motorcycles too. Motorcycle helmets would have speakers installed inside, wirelessly connected to the bike so that it produces realistic motorcycle sound effects when you operate the throttle.

This way, motorcycle enthusiasts could have all of their "loud pipe" thrills while riding a clean, silent electric motorcycle and not disturbing their neighbors!

For even more realism, vibrators could be installed in the seat to mimic a combustion engine's "vroom".

You joke, but they do this in cars.

https://motorandwheels.com/cars-with-active-sound-design/

These kinds of all-or-nothing approaches are not feasible - even in high-walkability scoring cities. Just look beyond your city's micro-core and see how reliant people are on cars - I'm talking places as diverse Oslo, Norway, Rome, Italy or Amsterdam, NL ( the HN bicyclist collective's favorite city ) [1]

People rely on cars for very valid, strong & un-substitute-able reasons in 1000s of cities on this planet ( even without counting the countries in the developing world which are just now getting a taste of vehicular freedom ). HN represents a tiny slice of of an already small slice of wishful thinkers whose pipe dreams get a dose of reality the moment you step outside your NIMBY bubble.

Even reduced car usage - in what is touted as the most bike-friendly city on earth at least here on HN - looks like this in the Baarsjes and Oud West neighborhoods of Amsterdam.

Een rondje door de Baarsjes en Oud West.

https://www.youtube.com/watch?v=yN7ox6bxBlI

this would also help stop people hooting unnecessarily, if they had to hear it themselves