Not remotely the same thing. HN's ads are text-only job postings for companies in YC's portfolio. "Online ads" on the other hand are an unregulated wasteland of scams, dropship brands, misinformation, titillation, and culture war ragebait.
True, but how many sites allow users to down-vote or flag the advertisements? A lot of the blatant ad posts wind up flag-killed and only people who have "show dead" enabled ever see them.