Is there much demand though for archive content on demand. Although it is there Netflix and Amazon have only grown to what they are today thanks to original content.
For some stuff yes. Anything universally popular like Fawlty Towers, Dad's Army, Keeping Up Appearances, etc will do well on demand on any platform. Amazon seems to have "picked up" a lot of BBC stuff though I suspect they're just leeching off the iPlayer feeds.
For anything else such as a random episode of Panorama in 1982, back episodes of Nationwide and old episodes of Brush Strokes (thank you Philomena Cunk
), then probably not. In fact I dare say 95% of the entire archive that sits on a server or tape format, once you get past the nostalgia part and sit through ten minutes of an episode you suddenly lose all interest in it.