Yes, I guess they’re called user scripts, but using tamper monkey or similar, you can add buttons to for instance Bandcamp or Discogs to auto fill info on Musicbrainz. Absolutely brilliant.

https://musicbrainz.org/doc/Guides/Userscripts

I used to collect CDs and adding them to Discogs was hell. Hated the work, but it was fun diving into obscure releases. Now I buy most of my music on Bandcamp and adding it to Musicbrainz is a breeze, especially with the website plugins.