TIL.

Thanks for sharing!

Edit: added quote below

By design, WebExtensions is more limited than the promiscuous extension mechanism. By design, it also works better. Most of the Firefox development tax has disappeared, as only the WebExtensions API needs to be protected, rather than the entire code of Firefox. Most of the maintenance tax has disappeared, as the WebExtensions API are stable (there have unfortunately been a few exceptions). It is also much simpler to use, lets add-on developers share code between Firefox and Chromium add-ons and should eventually make it easier to write extensions that work flawlessly on Desktop and Mobile.