It's a way to discover their content - content you might miss if you only go on HN once or twice a day.

HN is great for diversity of topics, tech news, random discussions with tech-celebs etc., but e.g. Simon's blog is the best content there is on what the latest LLM gizmo is and how well it works.

Tireless promo works. 3 of the top 5 authors on this list tirelessly promotes themselves everywhere - not just in HN.