Unfortunately, not all music that gets released is available on Bandcamp. I wish they all were, but it seems to usually just be the more ‘indie’ bands that are using it. Luckily, a lot of those ‘indie’ bands are quite brilliant.
On EPISODE 001 of ‘Mix Tape Radio on Folk Radio UK’, a handful of the tracks that made onto the mix are available via Bandcamp. And since those tracks are all great, I've added them to the ever growing playlist that is Bandcamp Radio.