I think the hard problems in social media is the social and business aspects.

The business side is figuring out a revenue stream. Choosing ads constrains your business models. But there may not be viable alternatives.

The social problems are trickier. Network effects, ensuring bad submissions are removed, etc. are all tricky problems in their own right.

Understand the sentiment, but I think that's much easier said than done!

The platform is the easy part, you can even just fork Mastodon. Content moderation is the hard part.

Everything is the hard part.