Are there still any services that run end-to-end Reading to Canterbury? I would imagine that there is a fairly healthy Reading to Gatwick usage, with separate Redhill to Canterbury (or Redhill to Tonbridge) service that has lower usage. And does it matter if few people made the end-to-end journey, if more people travelled between various intermediate stations? I would imagine there are lots of lines where few people travel from A to Z, but many travel from A to F, C to H, D to Z etc (where stations are in alphabetical order).
When I used to travel from Bracknell to Gatwick (to fly to/from my sister who lived in Boston at the time) it was a toss-up between Bracknell to Wokingham, wait almost half an hour (*), then Wokingham to Gatwick, versus Bracknell to Clapham Junction and then Clapham Junction to Gatwick, with a shorter delay but the need to get my suitcases further between platforms.
(*) Services on the Reading-Waterloo and Reading-Gatwick lines at Wokingham are timetabled badly for anyone wanting to make a Bracknell to Guildford/Gatwick connection because, in order to minimise the time and the number of occasions that the level crossing barriers are down, the Reading-Gatwick service leaves a few seconds before the Waterloo-Reading train arrives, and vice versa when going in the opposite direction. Or at least, that's how they timetabled it when I last used that service in the late 90s. Occasionally I managed the footbridge sprint if one train was running early and the other was running late, but more often we'd sit outside Wokingham, on the opposite side to the station, waiting until the train in the station was ready to leave, so that one closing of the barriers satisfied two trains moving in opposite directions simultaneously. Very frustrating to think "We arrived early enough that I could have caught the other train but we were stranded on the wrong side of the crossing even though the other train was running late."