Like all things it does depend on where you ride and the general driving culture. In America that’s how I ride but in Vietnam it’s very different. Road rules are not as often followed and honking is common to make yourself known, usually while there I wear lower db reduction ear protection.
I am also not saying that there is zero opportunity to hear a horn but already on a motorcycle you have to have so much more awareness that I don’t find that sounds are all that helpful. It absolutely applies to driving a car too, after driving a motorcycle for a while I am as shocked as you just how unaware drivers are of their surroundings.
Keep in mind at around 35mph you can easily hit 85-90db from the wind. I do think ear protection actually helps identifying sounds but I still argue the hearing part is not that helpful.
I am not trying to say you have to follow my methods but folks calling for criminal punishment and shaming are a bit too far as the safety benefit from hearing is quite minimal depending on the driving culture.
No.
For example, every beginner-advice thread in /r/motorcycle has a highly-upvoted comment(s) recommending ear protection, including many folks stating they wish they had started using it earlier.
And even if it is conceded that sound may not save you from other vehicles, ear pro(tection) reduces the health risk of hearing loss that would effect other aspects of your life.
Cars are quieter, and hearing other vehicles is more likely. If anyone shouldn't listen to music, it's car drivers, not motorcyclists.