Legally, use of horns in traffic is restricted, and abuse can be punished. Doesn’t keep people from honking all the time.
Tho I like the proposal to require that manufacturers design car horns to sound as loudly inside the cabin as outside. Might make a dent.
I myself pretty much never honk. I understand honking makes sense on narrow bendy roads like in the mountains, where you need to alert the drivers behind the corner, but I don't see any other legitimate reasons to be honest.