The platform is fine and being able to subscribe across Lemmy instances is nice (i.e. I'm not even on Beehaw but here I am anyway) - it just needs more users and content.
The main issue is going to be getting that critical mass of users, especially on a platform that isn't quite as straightforward as a centralized one. Trying to explain how Lemmy works to my wife just left her confused and wondering what the point was. Getting people like her to make the jump to a federated platform is going to take time, effort, and - most importantly - content.