You really nailed it with this comment. Napster is from another era when the thrill of discovery was much greater than it is now. Objectively maybe Napster isn't as great as all the nostalgia would have us believe. Maybe there are actually more songs on Spotify (probably not, but humor me). The thing is, back then, if you searched and didn't find today, it didn't mean you wouldn't find tomorrow. You never knew when you would find a gold mine of a collection that not only had what you were looking for but actually schooled you on a bunch of new stuff.
Napster was a magical moment where the underground went mainstream for a split second before being snuffed out. Of course these type of (smaller) communities still exist online, and music fans are better off than they ever were, but Napster embodied a sea change that could only happen once.