There are plenty of easy ways to serve up static files; but since every app needs to do it, Firebase has an integrated static file hosting solution.
Advantages of Firebase Hosting
Firebase Hosting is fully integrated with the rest of the Firebase platform. You can deploy easily from the command line. You can see those deploys on the Firebase Console and roll back to earlier versions if you break something.
Hosting supports URL redirects, URL rewrites, control over headers and default HTTP2 support.
You can easily connect a custom domain, and Firebase Hosting will automatically provision your SSL certificate, so you will always be protected by HTTPS.
And the icing on the cake is Firebase Hosting's integration with Cloud Functions. You can, with a couple of lines of configuration, redirect a URL on your Hosting domain to any of your HTTP-triggered Cloud Functions. Now you can serve up dynamic content in addition to your static files!
Disadvantages of Firebase Hosting
There aren't any. The headline is misleading.