Fedibridge

I think this would go a long way to helping. It won't necessary hold users, but will at least keep them from bouncing off of it so violently as this Reddit user did. Imo, its a combination of this with the lack of other content that prevents more significant growth on Lemmy. The rough, often politically focused onboarding, scares people, and then when they go to try and find their favorite communities, they see no activity, leaving the impression that the site is nothing but politics.