Bottlenecks also come up at the server side, even if your last mile can receive it the server can't send it as fUp to means you can expect a max of 100 mbps, but that's not a guarenteed speed you have at all times. right ?
That's how it is in Denmark. Many companies have changed it to "up to" because they don't want to pay for unnecessary bandwidth and such. Thus we experience that our internet may be slower during peek hours, while during nights you can achieve higher speed because rest of the country is sleeping
fast.
1 GB service is given over dedicated lines I guess. That is, unshared line end to end from the central office to the subscriber. The fact that the city governors charge too much as the landlord of the real estate of the backbone infrastructure prevents service providers from laying more lines and increasing capacity. At some point central government will have to interfere.