Why the hell is it so hard to find digital copies of Steven Wilson's Remixes/Remasters?

For the past couple of days, I've been searching for Steven Wilson's remasters as I have found them to be consistently incredible and more often than not they have become definitive versions of the respective source material. However, it seems as though they are only sold as cds/dvds/blu-rays and almost none of them are available for digital purchase. In fact, it looks every single album or song that is available for digital purchase is already available on spotify. So far I've had no luck finding King Crimson, Yes, XTC, or Hawkwind in digital releases. Am I just missing it or do these really only have physical releases?