My current side project is https://feedsub.com. Right now, - it's not great - I started by building an simple tool for getting regular updates from RSS feeds, but longer-term I want to turn this into a system which can absorb all the data streams you're interested in (news, stocks, weather, social, communities) and give you dials (filters, curation, signals, etc..) to surface a healthy amount wherever you want (SMS, email, web, RSS, chatbots, etc..).
The crux of the problem is endless scrolling feeds we're sucked into 24/7, which is why I based my MVP on email.
My current solution is trivial on a technical level. Honestly, my biggest problem is thinking about the problem on a non-technical level, balancing this with working life and branding, since my software and vision are very far apart right now.
(TBH, this isn't nearly as hard a problem as some of the others here - but I enjoy the ideas/feedback I get from communities like HN)