I recently moved back from London to San Francisco. In my 3 years in central London (N1) I had to use a 5g hotspot (thank you, Vodafone unlimited) to get anything close to fast internet in my flat. If I went with a wired "broadband" connection I could not get more than 10Mbps down. The street next to mine had gigabit fiber though.
The reason? Almost all utility cables in London are underground. So replacing internet infrastructure requires ripping up the street. I lived on the high street near a tube station so I guess they hadn't laid a new line near me in 10+ years. I was really shocked after calling 15+ internet companies and finding out that nobody could offer me higher speeds. Only different prices.
Now I moved back to San Francisco and I was excited to get some fast internet in my home. Quickly it became obvious that Comcast was my only real option at my address. They had plans up to 1200MBps down, but nothing over 20Mbps up! And 50%+ of the plans had data caps. I find a 1Gbps plan with a 500GB data cap hilarious ... theoretically you could use the entire data cap in ~75 minutes if you could saturate it. That's a lot less than a month!
So basically internet is a disaster in both countries but it sounds like this is a step in the right direction.