Public transport has an implication that generally people turn up for their transport and buy it.
Public transport is scheduled transport (trains, buses, planes) that everyone can buy a ticket for as long as they have the required funding. No difference between a bus, a train or a plane. You pay, you can get on. Whether you pay in advance or not. Whether you have red hair or black hair, are 20 or 40 (although for safety reasons there may be limitations to certain seats or means of public transport).
So an option not available to providers of other forms of so-called public transport is available to airlines. To expand - whereas anyone and everyone can get on a bus - absolutely no one can get on a plane without booking.
This means that the airlines do have the practical opportunity of deciding who goes on their flights and where they sit and therefore how far they are prepared to go to reasonably underwrite their advertising promises.
A provider cannot simply pick and choose who they want to buy a ticket! Apart from commercial implications have you thought about the ethics?
In this respect therefore air travel is completely different from public transport generally.
It's a bus. Even in the airline industry they call Y-PAX 'back-in-the-bus-traffic'
I would love to go everywhere on a private jet, but cannot. Also don't think it is necessary as I really cannot complain and will always do my utmost to ensure the best environment for everyone around me. Not perfect, but not so bad.
Buy a proper headset/earplug, set expectations appropriately and enjoy life.