Back in 2011, Google came out with authorship a way of Google understanding which content was written by which author, no matter what domain they posted their content on. So if you published at SER, SEL, Medium, etc, it would communicate that all those articles across multiple sites were written by the same author. Google killed authorship in 2014 and then two years later, gutted the rest of it from Google's features or backend.
So using rel="me", the Microformats no longer makes sense from at least a Google search perspective.
John Mueller from Google confirmed this on Twitter saying he isn't aware of how using it would be helpful to Google's algorithms.
Not that I'm aware of.
— John ☆.o(≧▽≦)o.☆ (@JohnMu) April 26, 2018
I do miss authorship, I loved seeing a face of who wrote the article in the search results interface. But I think SEOs abused it, I can be wrong, and Google dropped it.
Forum discussion at Twitter.