I find it hard to believe that 40% of the UK still only have access to ADSL only connections.

Thinkboardband have "superfast" (>24 Mbps) at 96.83% UK household/business coverage. 91% Openreach >30 Mbps coverage. Basically "Fibre" (FTTC/VDSL/G.fast/Cable/FTTP) has a 98.73% coverage atm. - https://labs.thinkbroadband.com/local/

VDSL (Pretty much the cheapest of the list above - though Virgin (Cable) have slower speed packages priced to compete with VDSL) comes in 3 flavours. Upto 38Mbps, Upto 50Mbbps and upto 80Mpbs (The upto depends on the copper cable quality and distance from modem to the Streetside VDSL cabinet).

The data they list is for ADSL2+ connections which max out in ideal worlds at 24Mpbs (When ADSL2+ was the fastest I could get I was getting 16Mpbs). Its dependant on the quality and the distance of the copper cable between the modem and the exchange the line is connected to, a much further distance)

With the push from ISP's to get more people onto VDSL or better lines the price between VDSL and ADSL is next to nothing (A cost differnce of £2 per month for my ISP).

I know many households that have been auto upgraded to VDSL by their ISP's (If you have a modem from recent years then the upgrade can happen without anyone even visiting the home).

For an example of an alt to ADSL. They live in London, they have decent 4g/5g coverage, a no contract pay per month unlimited data sim from Three cost £35 p/m and less if you commit to a contract period. I was happily pulling 100Mpbs down on that plan and using 2TB+ per month with 0 complaints from Three. Granted you have to have the luck of the draw of being in decent range of an non over utilised mast which would be harder in a more dense area like London.

Yes we still have blackspots (Mainly people who live a distance away from their closest cabinet) in the UK where connectivity is still shit and there are pushes and grants from the goverment to reduce those blackspots. I just don't buy the 40% of the UK number quoted. I think they mean that YT broke for 40% of the people still on ADSL connections.

To OP (if they are reading) buy a 4G router off eBay (They are cheap and slap a Three simcard in it and give it a spin to test speeds in your area), OK you are now going to be CGNAT'ed (on ipv4) but if that is a problem (it was rarely a problem for me) there are ways around that too using a £5 per month VPN - I lived with using a 4G connection for 12 Months just fine. I Feel bad for the people who live in the real sticks and don't have even that option to consider.

The bad parts of using a 4G conenction from Three? At the time I couldn't get IPv6 but towards the end of my time with them that was more down to my hardware than Three's problem. A slighlty higher ping then using a fixed line connection but I was happily playing online FPS's on the connection. And when I wanted to host a IPv4 server I had to use something like ngrok or spin up a VPN and tunnel to that and then use the VPN's ipv4 address. ngrok is easiler to set up but VPN will give you a static IP.

Oh and (if like what happened to me) if your local mast get knocked offline for what ever reason (A car driving into it for example... Yup that happened to me) you will have to use a mast thats further away which now has more users using it so speeds will get slower. On the plus side for that if soemone crashes into your local cabinet (Also happened to me but years prior) you are going to get knocked offline with no fallback until the cabinet operater comes out and repairs it.