I don't personally use Linkedin so I can't really comment on how a federated alternative would work or be useful for business.

What I will say is that paid/business-related and the general fediverse culture/design seems like oil and water. Especially the paid part. It simply won't take off unless there is a mass exodus of people from Linkedin (very unlikely). And even then, having multiple instances for something as focused on Linkedin doesn't seem viable. It's probably better off centralized and disconnected from a large network like the Fediverse, in my opinion.