VideoHomeSystem

(Opinions are my own) They don't. A site like HN isn't in the top 10,000 referrers and no one has ever heard of it; traffic from this exact post is barely a blip. There's no business value.

Teams responsible for backlinks would post on established social media in a very transparent way (from official accounts, etc.)

Besides everyone here has JS disabled, four ad blockers installed and uses a text-based browser. If I personally made the call they would never have employees (or paid contractors) post here of all places.