Six years ago, I nearly got my ISP to upgrade our fibre connection to 1Gbps. As I said at the time: This is a curmudgeonly post which is going to look ridiculously outdated in a few years. What's the point of Gigabit broadband? Well, it's a few years later and Virgin Media have just given me their Gig1 package for £30 per month. Nice! With all the inflation related price rises, it's great to …
No that’s not true, there is actually competition here and a very transparent market.
30 years ago when 2 Mbit/s was relatively new here, ADSL on existing phone lines had a price of 69,- €. (cheapest provider at the time)
Even without accounting for inflation, the price now is cheaper for 1 Gigabit, despite the old ADSL was based on existing cables! And 1 Gbit obviously is on fibre optic cables made specifically for internet connection.
The cost of establishing fiber networks was expensive, and it is only recently that some of the companies are turning decent profits, and I think most of the profit is on selling TV packs and extra services like cloud storage and virus protection. My internet bill has about 5 points of extra services that all have a nice round zero on them. 😋
I have made the measurements, and at 500 Mbit/s I actually got a bit more than 5x what I had at 100 Mbit/s. Actually my 500 Mbit connection ran as 550, because the rated speed here is the guaranteed speed of the connection. So the only limitation is the server at the other end.
It is true however that 1 Gbit/s didn’t quite double the 500 Mbit/s speed, Actual measured facts beat speculation.
But your examples of steeply diminishing returns are not true.