The Exchanges are the main cause of DSL failures locally - the DSlam cards often glitch, so much so we have had a monitor on the rack I’m connected to to reset some cards automatically. The old POTs lines fail in village cabinet now and them but over the last few years most of the connections have been replaced and the fibre between the cabinet and the exchange in the next village is reasonably new.
Oh for FTTPbut then again it took our MPs involvement to get broadband
You used to be able to find what rack and card you where on - handy when the OpenReach folk could check the other users to see if it was the card or not. Last year both a friend and I had exactly the same issue at the same time, I’m with EE and he was with Sky. Two engineers where sent (we live at opposite ends of the village) and ended up looking at the same card in the exchange. They still did not replace it