What you're arguing for here is what Google did - they didn't implement 'contain', so everyone got the equivalent of the Safari browser experience. If Google had done what I'm suggesting here then users who are on Chrome, Firefox, Edge, etc would have a much better experience. Safari users wouldn't see any difference. Why would you make the user experience for many people worse than it could just because they don't use Safari?
Everyone should get the best possible experience for their chosen browser, even if that means users get different experiences.
> "they didn't implement 'contain', so everyone got the equivalent of the Safari browser experience."
Not sure that the Google developers knew that feature existed. Most people in this comment thread were unaware of this feature too, seems reasonable that the Google developers might not have been aware either.
> "Everyone should get the best possible experience for their chosen browser, even if that means users get different experiences."
I like that quote. Good websites do give the best experience a device can handle, rather than cater to what the worst devices are capable of.
Everyone should get the best possible experience for their chosen browser, even if that means users get different experiences.