This article was written in 2016. It might or it might not be outdated. And it could be that the layout breaks. If that’s the case please let me know.
I’ve always been a proponent of progressive enhancement. I promoted it with clients when I still had those, and I teach it to my students now that I’m a lecturer. But this will have to change. Heydon Pickering, a true master in using valid arguments, wrote this very convincing article called Progressive Enhancement Makes Me Sad. Here’s one final reason not to use it: We do not want sad Heydons.