They are still a minority of sources, many of the newsy ones have non-paywalled articles. I may not notice some paywalls because I usually have JS off so a lot of paywalls do not work.
They are also a pick of the most interesting articles. its a very small proportion of what is available.
> Who reads the original news might have a better understanding of the topic, might be a better, clearer writer, can add context that makes sense for their audience
Might! If you want original sources read Reuters - non-paywalled BTW.
> because there is still added value in some journalism (true journalism, we might call it?).
Good journalism is a rarity. It is, and has always, been far less common than sloppy, inaccurate, and sensationalist repporting: https://en.wikipedia.org/wiki/Gell-Mann_amnesia_effect
Because a lot of HN voters and commenters just read the headlines and not the articles.