> Is there any benefit to duplicating the implementation of business logic for each micro frontend
Im not too sure what else I can say that hasn't already been said. No coupling between the frontends means the complexity of the overall system doesn't go up with the amount of them you have and your organization can scale to infinity without increasing coordination. The architecture is best suited when you have a lot of distinct things (so duplication exists, but is kept to a minimum). You can still share stuff to avoid duplication in key parts. Injecting scripts, iframes, deep linking. Those are the frontend equivalents to backend microservices "service boundaries".
Im not too sure what else I can say that hasn't already been said. No coupling between the frontends means the complexity of the overall system doesn't go up with the amount of them you have and your organization can scale to infinity without increasing coordination. The architecture is best suited when you have a lot of distinct things (so duplication exists, but is kept to a minimum). You can still share stuff to avoid duplication in key parts. Injecting scripts, iframes, deep linking. Those are the frontend equivalents to backend microservices "service boundaries".