While it’s not ideal for most subreddits, I do get why they do this in general. A lot of subreddits prior to the API protests already had a Discord server where the community would congregate. I was already in r/deadmau5’s Discord server during the COVID pandemic, and it used to be the official Discord for electronic musician deadmau5 and his label to the point where he and his label signees would actually talk in there. That was changed after his management decided to try integrating crypto/NFT shit into it which the owner of the server disagreed with, but the point still stands.