What are car horns supposed to be for? Ok, warning people people of your impending arrival. But - if you need to blow your horn for that, you are going too fast.
Horns are largely used as a means of venting anger at other motorists, by taxis to announce their arrival to clients and to notify your acquaintance who is walking down the street that you have seen them. None of these is a valid use.
They're too loud. If used to warn a pedestrian with their back to you in a narrow lane that you can't get past, they will jump out of their skin, try opening the window and asking politely instead. A pedestrian warning tone rather like a front door bell might be a good idea.
The solution? Ban them, simply build cars without them. They're unnecessary.
If you agree, toot your support as you go past The Old Mill.