I think they mean serverless here more about the user experience because the user doesn't have to install a server to make it possible. Because there is here a

I think they mean serverless here more about the user experience because the user doesn't have to install a server to make it possible. Because there is here as you mentionned Oauth.io server, but also Github server and lots of other servers for fonts/librairies etc... Nothing is technically "serverless" on the web ;)