Looks pretty cool. Some comments on usability, It would be handy to see a visual indicator of which capabilities where missing from each browser - maybe you could colour each section heading Green or Red? It would also be handy if you could toggle all open/closed.
It might not be the objective of the owner of that site, but what I'd really like is an updated/maintained subset of what PWA features/components are usable across a selection of browsers - like iOS Safari and stock Android Chrome, Or Chrome/Safari/Firefox on desktop (perhaps filterable by OS too)?
I really like those ideas for filtering, thank you!
> It would also be handy if you could toggle all open/closed.
Added, thanks! I really like the suggestion to use some kind of indicator in category headings, too.