An excellent new utility called PiPifier was just launched by developer Arno Appenzeller. PiPifier may sound familiar, as it was originally released as a macOS app on the Mac App Store. But now the app had made its way to the iPad.
PiPifier is a tool that enables viewing any HTML5 video using the iPad's Picture in Picture feature. It works as an action extension from the share sheet that you run within Safari. Simply load a site containing a video, then run the PiPifier action extension, and the video will instantly enter Picture in Picture mode. This is tremendously useful on sites like YouTube that do not support Picture in Picture by default, and in my testing has worked perfectly.
PiPifier is a free download on the App Store.