I remember a video + blog post about this, and it was suggested to just ship a mobile layout for browsers that don't support css grid. At least for personal sites that seemed reasonable.
Terrific, I can't wait for what will happen with the forced content filter that will be voted on in the european parliament on june 20th. what could go wrong...
Additionaly there is also this picture from Julia Reda: https://pbs.twimg.com/media/Dm5kGq5X0AANQZs.jpg
Source: https://twitter.com/Senficon/status/1039881088078958592