You do realize that we are on a platform without ads where your word is heard, so it still is possible.
And before "social media" there were plenty of free forums (each with a certain main topic, but in which people were discussing occasionally more than that), so it was not that bad. And in fact that continues today (ex: this one), with more relevant discussions in my opinion than what I glimpse from my occasional social media incursions.
It's a place with bait for software engineers (lots of tech stories and discussion), and YC then gets lots of eyes on job postings for their companies. This is explicitly why it exists.
What is your threshold of what you consider advertisement?
In the same way, speaking with a friend (or anybody) can be seen as "advertising your ideas".
For me, HN is more of an open discussion forum, where you can find lots of critical opinions on the topics, which for me makes it less "advertisement" than lot of other things.
You do realize that we are on a platform without ads where your word is heard, so it still is possible.
And before "social media" there were plenty of free forums (each with a certain main topic, but in which people were discussing occasionally more than that), so it was not that bad. And in fact that continues today (ex: this one), with more relevant discussions in my opinion than what I glimpse from my occasional social media incursions.