It isn’t about digital vs physical it’s about ownership. On PC stores you’re still downloading a computer file. That you keep.

PlayStation digital isn’t like PC digital, it isn’t a file that you store on a hard drive it’s an entry in a database to say that you “own” that game. An entry that can be easily deleted whenever Sony feel like it. Think of it like the difference between Netflix and Jellyfin hosting.

Just like Netflix Sony can take away content whenever they want. At least with Netflix they don’t try and claim that I own anything though.