Almost all of the houses built on Grand Designs, Building the Dream
etc, very rarely have a doorbell or other entry system. Seems bonkers
to me that the only way of knowing there's a visitor to a, usually,
large house is is by them making a loud enough noise banging on the
door to overcome the radio/TV etc. And it wouldn't cost much in a
new-build.
Of course, there's an opening for Dave TMH to install wireless
doorbells ...