"To be honest given how few services actually need more than 20Mb/s that might be quite sensible."
Yeah. I'm on VM BB and it's fine. Without being on certain benefits and dropping to a cheaper "social" tariff, the minimum priced BB I can get from them is 120Mb/s. For me, that's massive overkill 99% of the time. And I can't even use it because my home network was "leading edge" back in the day when a dual 100Mb/s NIC in the firewall PC was the bees knees :-) I really ought to upgrade it one of these days. Internally, I now have a GB switch, so those newer devices on the LAN can talk to each other and the server more quickly apart from the WiFi devices because the repurposed WAP is only 2.4GHz.
In a way, my LAN+external connection is a reflection of what the poster above said about Spain and UK infrastructure. Spains is newer and better, UK was good but is older. You can't just swap out/upgrade an entire infrastructure quickly, easily or cheaply. There's a sort of leap-frog effect with big infrastructure. Some 3rd world countries have far better mobile coverage and pricing than UK or EU countries because they were building out from scratch with the latest 3/4/5G kit, not looking at the ROI on the 2/3G kit and a nationwide copper wired network. Assuming a "perfect" world and ignoring money-grabbing, incompetence etc that seems to be rampant in any large operation. If you just spent £20B on a network and have made £10B profits so far from it, you're not going to rip it out and upgrade to latest shiny just because your neighbour has the latest shiny without a very compelling reason. For the vast majority of the UK, current speeds are adequate, and most can easily more if the want it. (Although I admit and agree there are users left in the shit, even quite close or even inside major urban areas)