Cwmcarn’s uplift is aimed at the DH trails. Y Mynydd and Pedalhounds. The best one, Y Mynydd is effectively shut as they can’t run the bus up there at the moment. Though you could ride/push but it’s a killer.
Twrch and Cafall are regular trails and the idea is you climb them. They’re long enough to take a few hours on average so you’re not going to get much out of an uplift day pass, which gets you some way up on Cafall and isn’t running the other side anyway so Twrch is still a climb.
As for being unpopular, that’s popularity of BPW at fault combined with the logging on the Y Mynydd side.
They used to have two busses but cut backs meant they got rid of one, and even that one isn’t majorly busy.
Sad really. Used to be well worth an uplift day for Y Mynydd and used to be busy.