Just in the same home I live - there are at least 5 home-networks (in 16 flats) according to the visible WAN access points with good quality of the signal.
And I suppose all others use Internet in some way on one computer or network without WAN access.
There are generally 2 underliyng providers - Telephone company and Cabel TV. So I suppose 5-10 flats in this building use the same cabel for their Internet access as I am.
And I'm not living in the desert, so it is not only building using same network... So if I want to get 1Gbit channel - I do not feel - 16Tbit channel used by High level provider will be too much...