Installing Ethernet cables

Yup fair point, and to an extent I let where phones would likely be required to be a driver in the layout.

So for example, in bedrooms I ran out four pairs typically - one positioned where a phone close to the bed would be most likely required, and then the second where you might have a TV or computer etc.

Having said that, at least with phones, you can split one port to support up to 4 analogue phones if required (although you will get some crosstalk from the ring signal bleeding through to other lines).

Not everyone lives in a cave, Turnip. And has caveman views.

Lent one to next door when her landline was done. Worked OK there. So through two 9" brick walls.

Do you live in a soundproofed building? ;-)

probably depends on the bricks. This house has very hard (1910ish) ones.

Some people use foil backed plasterboard in "modernisation" situations,

I had a colleague whose cottage had stone dividing walls. Even FM radio couldn't penertrate.