Both those sites existed - either in practice or in concept - for well over a decade now. If the giant mega corporation behind those products is blaming WebKit,

Both those sites existed - either in practice or in concept - for well over a decade now. If the giant mega corporation behind those products is blaming WebKit, maybe they should instead devote some engineering resources to just work around the bug. Testing in non-Chrome browsers should identify anything like this before stuff ships. It is legitimately not hard to do.