An open source browser can not render standard web pages. A browser can either be open source and unable to render DRM content, or it can contain closed-source

An open source browser can not render standard web pages. A browser can either be open source and unable to render DRM content, or it can contain closed-source components and be able to render DRM content. Firefox + Widevine is the second kind, Firefox without Widevine is the first kind. It is illegal to make a fully open source browser which can render any standard web page.