You lost me at “recommendation engine”. I want to follow users and subject specific hashtags. I want control. I want privacy. Not greedy black box AI BS. Plenty free options for content exist today and I am perfectly happy barely paying for anything as is.
The problem you describe is not a problem. Think about drastically narrowing the scope. Find a couple users in some extremely underserved niché and study them instead of the developers here. Solve problems that come out from what they tell you/what you see.