Not always true, but in the case of MB metadata, yes, since we are far to have an advanced AI to do the work 
(see The Stanford Question Answering Dataset for AI vs humans…)
On topic, we need both quantity & quality, and Discogs clearly beats MB on quantity, while quality is far from bad. Discogs is considered as a reliable source by all editors, though, of course, it has errors (MB too…).
Ijabz identified a bunch of artists for which Discogs links are missing, i see nothing wrong in trying to improve the situation, as it would help editors & users.