I presume you could subscribe and still use this tool? People use automation tools like this to download things that they already pay for because it saves them the effort of logging into 5 different apps depending on which walled garden it's in.
It’s Bandcamp: you buy the album and they give you a link to download it in whatever format you want so you can listen to it using whatever app or device you wish. You can come back later and download it as many times as you like.
What if I don't want to manually follow links or "come back later", but just add the album I purchased to the config for the same script I use for the rest of my media library?
Do artists get paid on Bandcamp if they bypass the login?