The correct comparison is JWT vs sessions, not JWT vs cookies. Cookies are a storage mechanism, and you would compare them to localStorage. Assuming you meant JWT vs sessions, yes, there aren't any except that it's super trendy.

They let you answer the question "did some other machine I trust find this entity to be a valid user, having this identity and the rights they assert they have?" without asking that machine directly or storing anything about the user. More or less. Provided the keys haven't leaked, of course.

The chief difficulty this introduces is manually invalidating tokens. You end up having to store some data and/or ask some other system questions about users (blacklist-related, in either case) after all, reducing the initial benefit. But distributed sessions will run into similar problems anyway.

Basically if your auth lives the same place as all parts of your application the user will ever see, don't bother with it because the benefit is little to none, otherwise, JWT's a solid maybe.

A server can issue a JWT and forget about it. Most cookie auth strategies requires the server to persist the token to confirm validity. Also, a JWT can work across a microservice architecture easily for the same reasons.

technically you keep some session data on the client which would normally be kept on the server