This is an amazing feature you simply don't need on the majority of web apps, because a) the browser has a loading indicator and b) most web apps are fast enoug

This is an amazing feature you simply don't need on the majority of web apps, because a) the browser has a loading indicator and b) most web apps are fast enough to not need to tell the user about it, they just load new pages in milliseconds instead. An in-page progress bar is in most cases a failure of UX, not a success.