We're in a somewhat similar position, AA and BT reached deadlock on our DSL with BT declining any further action on high error rates or PPP lockups on the basis that these are supposedly caused by an electric fence. That's an electric fence alongside a 50 pair cable, which apparently affects our line but nobody else. Honestly I was quite wound up about this at the time, but I am now over it.
On the plus side BT have in fact cleaned up the line, knocked a couple of dB off the attenuation and increased synch speed by around 15-20%. AA on their part have completely disabled DLM so an error rate of 2800 ES/hour doesn't actually slow the line down at all. The lock ups are still a real nuisance, sometimes only once every few days but sometimes constantly for hours on end.
The solution for me is 4G, and that works perfectly well for video conferencing as I've found working from home since Spring 2020. As a matter of fact Webex doesn't use that much bandwidth, MS Teams is more needy and really needs more than ADSL upload in any case. I'm using Three on Band 20 giving around 20meg down and 10 up.
The only 4G issues I experienced were with Smarty where some services including my employer's CRM objected when we started getting second by second IP address changes. Smarty never owned up to any changes in their CGNAT, but moving to Three with a real IP put that problem behind me.
