Its not really weird if you look at it in context.
People who are not Gen-Z whipper-snappers will recall the era.
Before cell phones, before DECT home phones, before wireless cordless home phones you had fixed phones.
You had a master socket and then, optionally, one or more secondary sockets (depending where you lived, you were either permitted to install these secondary sockets yourself, or you had to call in the telco to do it).
Anyway, so what would happen is that your friend from school would call you up. Inevitably your parent would answer the phone because they were, for example, in the kitchen cooking your dinner.
There would then be a shout across the house "Bobby its Johnny ... AGAIN !".
The call-transfer process would involve your parent hanging up and you picking up the nearest secondary handset.
Hence the exchange needed to keep the A-end of the call live whilst you completed the B-end "transfer".
The same generation of people will also recall the ability to abuse the mechanism to quietly spy on someone else using the phone. :)
UK analogue strowger exchanges did not permit the called party to clear down the line - that was the job of the calling party. A legacy function of being 'patched through'.
"Called Subscriber Held", a feature that was carried into early digital exchanges because people expected it to work in the manner you describe, even though afaik it was designed for the other purpose of keeping the line open whilst operators patched it through, trunk lines picked up the tone, etc.
My grandpa was a something like chief engineer for the West Coast of Scotland phone network. I have so many questions I wish I could ask him these days.
... although they can hear each other through the devices in their hands. More likely the person in the kitchen just put the handset down on the table and continued cooking.
It's still weird and unnecessary. This happened everywhere, but people just picked up the phone before the other person in the house would hang up. You mention it yourself because of the ability to spy.
Its not really weird if you look at it in context.
People who are not Gen-Z whipper-snappers will recall the era.
Before cell phones, before DECT home phones, before wireless cordless home phones you had fixed phones.
You had a master socket and then, optionally, one or more secondary sockets (depending where you lived, you were either permitted to install these secondary sockets yourself, or you had to call in the telco to do it).
Anyway, so what would happen is that your friend from school would call you up. Inevitably your parent would answer the phone because they were, for example, in the kitchen cooking your dinner.
There would then be a shout across the house "Bobby its Johnny ... AGAIN !".
The call-transfer process would involve your parent hanging up and you picking up the nearest secondary handset.
Hence the exchange needed to keep the A-end of the call live whilst you completed the B-end "transfer".
The same generation of people will also recall the ability to abuse the mechanism to quietly spy on someone else using the phone. :)