IMO, HN comments generally exceed the value of the story linked. Wikipedia suggest you really can scale content without Advertising. For major news organizations you have things like NPR that again work fine. I also brows plenty of forms that may or may not have a banner ad at the top and both models work.
In the wider realm it's a mixed bag, but advertising really does not seem necessary.
HN comments wouldn't exist without the stories to talk about in the first place, otherwise it's just a message board, which have been basically free to host for a decade.
Wikipedia is an outlier that goes through intense fundraising to survive. It also does not produce content.
Media publications are businesses and they need to make money to survive. Donations never work and if you tried to pitch that as the business model at even the hippiest startup convention, you'd be laughed off. Subscriptions do work but the public does not understand how to price the value and would rather go to starbucks instead, clearly seen in the endless comments and downvotes on HN when there is paywalled story or advertising talk. Subscription also bring up the issue of access for people without the means to buy.
20% of NPR's funding comes from corporations. Useful yes, required no.
It feels like advertising, but in practice it's virtue signaling. Much like giving to Habitat for humanity corporations want recognition for their donations, but as pure advertising it's not worth it. So, if they where not mentioned on air corporations would likely cut back, but not to zero.
Cool, let's just take away 20% of the revenue then and see if it's required or not. As quoted on that page: "Sponsorship from local companies and organizations is the second largest source of support to stations."
Virtue signaling is still advertising, paying money for exposure. Otherwise it's a corporate donation and that does not scale at all. You can look at the continuous travails of open-source projects that deliver billions in value but get no funding as a perfect example.
The point is that NPR comes nowhere near the massive amount of content that people consume but don't pay for. Please don't just assume the entire industry is incompetent, there are millions of people working in these media companies and they are constantly trying new options. So far, outside of subscriptions for certain high-end brands like the Financial Times, advertising is the only sustainable model found.
I am not saying the industry is irrational, I am saying it's output is mostly irrelevant to me. Further, advertising supported media is consistently the least valuable segment (to me) because they don't need to be as good to continue. They maximize profits by minimum effort and maximum views which creates mountains of meaningless drivial targeting emotional resonance.
Click bait is an outgrowth of payment in eyeballs.
As to virtue signaling, I bring that up because it can occur even if they are never mentioned on air. A company can say they are a corporate sponsor of X even if X only ever mentioned them on an obscure part of their website. In the world of virtue signaling simply accepting money creates vale. NPR is behaving rationally to accept as much money as possible and even to put effort into getting more because at effectively 90% the funding they would create less value, but clearly they could still create significant value with 90% of their current funds.
I'm not sure what point you're trying to make now. Your original comment was that you would be fine if ad-supported publishing went away because there are other models. I'm telling you that there are none that come close to the scale of advertising. The examples you cited either do not produce content or are a microscopic part of the media landscape. Tastes are also subjective and what you call low-quality might be exactly what someone else is looking for.
Anyways, if advertising went away, a massive amount of media you see today would also disappear. You would definitely notice that.
And that's before even getting to the even more massive impact it would make on the economy since every major company today relies on advertising for growth and sales. It's easy to look at few annoying banner ads and say that they suck, but this is a 12-figure global industry that plays a critical part in the economy. It's just not that simple.
The only TV I watch is the Olymics, would it go away without advertising well possibly. I bring that up because my habits are well outside the norm. Would I be aware of 95% of the news disappearing sure, would it directly impact me well probably not.
Advertising is largely zero sum, it increases the cost of products while increasing individual product sales. People would buy almost exactly the same amount of food for example without any advertising so that's pure dead weight to society. Despite all those car ads people would still buy a car without them further without that massive cost those cars would be either cheaper or better, etc across a huge range of industries. Without ads people would still buy soap and other home goods, at worst they would pay less when doing so.
In the wider realm it's a mixed bag, but advertising really does not seem necessary.