I also think news and memes are the exact two things we have in abundance. And I mean we already got a million other online places to read the news. What I like is the more personal things. What people genuinely care about. Their hobby projects, what you soldered/programmed/knitted/drew/... favourite computer games, books, fandoms...
I think one of the great things about platforms who have more content than we do is, how you can find stuff about every niche interest, including people to talk to. Thely'll talk about doing hobby horsing, painting minifigures, soldering lightning sensors, producing music with Free Software. And as a user you can read about all kinds of fascinating, sometimes weird stuff... You can easily find similar-minded people within the communities. I think we could use a bit more of that. Pretty much everything that isn't news or just copied from some other place.
We already have some of that. For example I see people post nice pictures they took. Of animals, or from spectacular locations. The dull men's club has a lot of genuine stuff from people's lives... And I can find people to talk to about Star Trek and some of my computer and electronics interests. I think the threaded part of the Fediverse is ideal for that kind of content. But we kinda need a broader bandwidth of stuff. And not only content, but the community of people who care and talk about it.