I’m not sure that actually works. You can search for a Mastodon user, but when you try to subscribe the sidebar buttons are missing on Lemmy.
My understanding is that you can subscribe to a Lemmy community in Mastodon, but not the other way around. Maybe there’s a trick I’m missing?
I would say Mastodon already has. I’ve been spending a lot of time there over last few weeks and there’s more content than I can consume. Breaking news stories are covered well, including live blogging, although a lot of that content is cross-posed from Xitter. Plenty of people to follow, including authors, photographers, journalists and scientists. An increasing number of media outlets have a presence there, as well.
Xitter still has an order of magnitude more users, but Mastodon is mostly Nazi-free (which is nice).