There’s also site rules and capabilities.
For example - Discogs wants separate entries for John Smith, the real name of the guy known as Artist X. And they want all bands Artist X is in, to be listed under John Smith, not Artist X.
I don’t go to a KISS concert and scream “hey Chaim Weitz, spit blood on me”.
And then, trying to import the data from Discogs, MusicBrainz ends up with two artist pages. Chaim Weitz as the bass player for KISS, and Chaim Weitz performs as Gene Simmons.
Whereas MB wants one page. Gene Simmons to be the bass player for KISS with a legal name alias of Chaim Weitz.
**of course, that is not really a related example because it deals with people instead of releases. But I think it conveys the point. We are us. We do what we do. They are them. They do what they do.