Without long text, to a good approximation, you just can't convey long, multi-step reasoning chains at the limit of human intellectual capacity.
Personally I've started reading again much more recently, and it's done wonders for what's going on inside my head. I was feeling so dull! I can only recommend it.
Non-fiction is very good for other reasons and it's good to aim for a healthy mix of the too I think.
Walk into a library or bookstore. Pick up something that looks interesting (LITERALLY judge a book by its cover for this) and start reading right then and there. If the book doesn't capture your interest immediately, maybe skim a little bit, or just move on to the next book. Also, ask trusted friends that know you well for suggestions.
You have to first know what your own particular tastes are, and afterwards, do the harder steps of understanding why you like what you like, and expanding your horizons. Once you get to the point where you both know what you like and start to know why you like it, discovery just solves itself. Eventually, you'll be able to tune into any random discussion about a book or author, and discern from context whether or not the works in question are for you, even if you don't share the opinions of those you're listening to.
I've also listened to some YouTube channels who review or go through books they've read. Of course it's important to find someone who have similar taste to you or you'll have a bad time.
On the point of "alternate history" I'll throw out "Matt's fantasy Book Reviews" YouTube channel where he also has some alternate history type books he brings up from time to time.
Fiction has so much more to offer! On top of what you wrote, fiction helps you to develop an ability to put yourself in others' shoes. Empathy is anyway scarce in this politically-charged and ragebait-filled world.
Fiction has helped me develop empathy and to stay empathetic. It has helped me develop my philosophy of life; morals and values I strive to stay close to. The fictional characters have given me courage during hard times. And so much more.
Lot of people prefer to start with self-help kind of non-fiction which is, IMO, the least helpful category of books. I don't know what draw people to it.
It seems very far fetched that an app that looks like HN might become as popular as TikTok, and that's because the TikTok format is excellent at creating something that pulls people in by delivering short term rewards.
I'm not a Luddite, I'm sure there are some creators out there making clever tiktok videos, but that format really isn't conducive to, as you say, "long-term, coherent narrative building and multistep reasoning".
Edit (addition):
How the fuck did we decide that a large language model somehow became artificial intelligence? It’s like claiming a dictionary is intelligent. I just don’t get it.
"Go Read a book" was really meant to be synonymous with "Go educate yourself"
No one really says "Go read a blog" or "Go read your facebook feed" the same way, at least as far as I know.
I sure hope "go spend more time on social media" or "go talk to an AI" never becomes synonymous with "educate yourself". I shudder at the thought
"Go consume this form-factor because it's better" has always bothered me.
https://en.m.wikipedia.org/wiki/Licensing_of_the_Press_Act_1...
The scale and pace of modern changes have absolutely nothing to do with what we witnessed thousands or even hundreds years ago. Word of mouth in 1700 can also propagate propaganda but no one is going to argue 1700s word of mouth propaganda is "the same" as foreign propaganda being served straight to your citizen through third party services 24/7
All propaganda isn't created equal either. If 99% of the news you get comes from the state owned journal and the state owned radio you're drinking your own Kool aid, if the propaganda comes from a foreign source straight to your population through third party services you have a whole bunch of different problems
For what its worth, 500 years ago people were just as worried about books as we are today about newsfeeds. But it took a long time for books to ultimately decentralize enough to become a more egalitarian, community knowledge. But even that's not entirely the case now. Books can be propaganda just like everything else.