When I think back to the 60s and 70s, when I was buying vinyl, my main memory is of the number of faulty LPs I bought that had to be returned to the retailer. I think it is great to buy CDs which have a 99.99% chance of being flawless. I am sure that vinyl quality control has been greatly enhanced since then, particularly since it is now the chosen medium of audiophiles. That said, I have no desire to go back to vinyl.
On the other point you make about the proliferation of download compilations, there have been just over 200 download compilations of Springfields' material since I started logging them in July 2014. That averages out at around 80 per annum. As to what you say about the likelihood of some of these compilations having had no sales, we will never know. However, someone must be buying some of them; otherwise the releases would have dried up by now.
The great majority of these releases are credited to DS rather than to The Springfields and their artwork features Dusty rather than the group. It makes me wonder whether a significant proportion are bought in error.