Why is getaddrinfo considered a legacy API? I understand that you probably don’t call this when you write software on top of Apples frameworks but it is a pretty standard thing to call for “Unix” (for lack of better term) programs.

For quite some versions that modern networking APIs on macOS using Objective-C frameworks, starting in 2018.

See WWDC 2018's "Introducing Network.framework, A modern alternative to sockets".

NeXTSTEP might have been a UNIX, and macOS derives from it, but the whole UNIX story has always been to bring UNIX software into the platform, not to make it easier to move elsewhere.

Duplicate: https://news.ycombinator.com/item?id=41571862

Well actually, that submission is a duplicate of this one and was posted 5 hours later.

Fair point. I didn't see the submission times, just the number of comments.