This is the moment for lemmy. The big issue this system had was it's viability. It was tiny. Like you'd look around at dead instances proudly reporting their double digit monthly user count with several day old threads and no comments.
I know I've taken a look at lemmy for a few times and decided not to take the plunge because while I wanted a smaller alternative to reddit, it was too small. We're at a point now where things are active enough to draw in a stream of content and the snowball rolling downhill will eventually grow into an avalanche.
I dont think a federated open source reddit alternative is going to reach the hundreds of millions of users reddit got, but that doesnt matter. What matters is there's enough people around to sustain a decent community.