An absurdly well designed, informative set of case studies that give you insight into product psychology, ethical growth strategies, and just excellent ideas that you can incorporate into your own products.
Once you get your head around Anytype, I'd argue this is far more powerful than Notion. That, combined with privacy-focused data ownership model, a transparent philosophy on monetization, a public roadmap, and plenty of documentation to give you the tools to make Anytype work just how you want, it's hard not to love it!