I think it benefits if, for example, you want to share your article with someone who has asked you for advice on another platform.

For example, someone asks me something on Twitter and is not a Medium user, so I can send them a link to my article on the topic they are asking me about instead of answering their question and wasting time.

In that sense I see it useful.

And also, if the person likes it, they can then subscribe to Medium.