Try to keep your client as dumb as possible, to achieve this you should avoid the following:
- performing complex business validations on FE
- creating sources of truth for entity types on the FE (consider a shared schema)
- making too many decisions about what data/ view is available on the FE
In many cases your service layer can take the heavy lift away from the FE which takes away complexity/ risk and avoids duplicating/ mutating business logic + domain sources of truth.