Independent of this thread I had reason to go to the website of a provider mentioned several times in it, and occasionally elsewhere on these forums.
Namely
Amvia. Quite small but look from a short look at their finances at Companies House seem to be viable. However I was a little disturbed to read the following

!:
BT's FTTC product is called BT Infinity
It is delivered using fibre to the distribution box, then VDSL over the final copper loop. There are two variants of BT Infinity, Unlimited Infinity and Premium Infinity. Unlimited Infinity & Premium Infinity only offer guaranteed speeds of up to 22Mbps download and 3Mbps upload. These speeds are considerably less than the capability of FTTC. The only difference between Unlimited and Premium is that Premium has PC support and Symantec security protection for your desktop devices.
...
©2022 Amvia Ltd.
It's at the start of a comparison of FTTC providers. The only other "major providers" of FTTC being TalkTalk and Virgin Media. (They do explain that VM use a different technology).
I think I know why the page is so out of date, and given the reason it probably isn't anything to worry about. Hence the "laugh" icon in the post header.
Connections: OnePlus 8 Pro on Three 4+ (LTE)/5G and at home Three Mobile, with (Three)ZTE MF286D router giving about 113/20Mbps.
The best of all possible countries.