Once again, with feeling: comparing this to fibre is apples to oranges. The bandwidths quoted for wireless are the absolute maximum, for a single user, close to the base station, with nobody else using that cell. If there are multiple users, the bandwidth is split between them. So for a 1Gb/s cell, 10 simultaneous users get 100Mb/s each, 100 users get 10 Mb/s.
The bandwidths quoted for fibre, on the other hand, are per connection. In a neighborhood where everyone is connected by fibre, every household gets the full bandwidth they subscribed for, no matter how many of their neighbours happen to be online at the same time.
