The US used to have laws that would have made the current situation illegal. They didn't make much sense for internet news, but they did for radio, television and newspapers.
They were repealed, and each time a law was repealed there was a direct financial tie between the politicians that repealed the laws and the networks that stood to gain. Post consolidation, the networks started running propaganda for the party that enabled the merger.
I don't have a great solution for the current firehose of foreign propaganda, but restoring market ownership rules (no TV, radio or local newspaper owner can have more than, say 25% of the viewership/readership of a given city with over N million people) would definitely help.
They could apply this to the internet by restricting editorial control to the editors of each publication. This would immediately force Twitter, Facebook, Google and Apple to change how they aggregate news content.
Concretely, Apple News could be made OK with minor changes: Apple would need to eliminate algorithmic ranking of articles, and replace it with algorithmic ranking of periodicals. Facebook could recommend you follow newspapers and magazines, but would not be allowed to intermingle the feeds. I'm sure the platforms would argue that this is unworkable, but we already have an existence proof. Podcasts work this way, and most people (here) would argue that they're a much healthier ecosystem than written internet news.
For one thing, there's no such thing as clickbait with podcasts. For another, you can cut off an editor with one click if you notice ragebait or sloppy journalism. None of the internet news aggregators allow you to do either of those things.
As for HN (assuming its readership is above some threshold), it would end up turning into a collection of blogs and syndicated tech columnists. I'd have mixed feelings about that, but I suspect having a collaboratively edited RSS feed with independently curated (by Dang and friends) comment sections on each article would be fantastic.