We're also trying to find the "hook" that would make such a site more useful to newsletter readers.
For individual articles, do you find sites like Hacker News or Reddit good for that purpose? I think there are certain authors whose writing is consistently good, and those are the ones we're trying to identify -- curious what you think.
I looked into scraping substack to find individual writers and highly rated ones (through subscriber counts). There's some good writers like Heated by Emily Atkin. Though - do I want to read climate change articles all the time? I found that for some newsletters I lost interest after some time or some topics didn't interest me.
Reddit is also a crowdsourced recommendation system with its subreddits. I find some subreddits good like r/dataisbeautiful. I found this subreddit through a referral from a friend.
People use twitter to ask for good newsletters as well.