> I agree that you cannot go from HTML to XHTML because users and UA devs will always go towards "it mostly works".
That... is not how anything happened.
> I don't see the same problem in other formats like JPEG or PNG where you expect the image to work perfectly or fail with a decoding error.
Browsers absolutely decode as much as they can, and if the file is corrupted halfway through you generally get garbling, not the entire image being replaced by "fuck off". The only case where that is so is if the browser can't parse anything at all, or can't retrieve the file.
> Other than implementing it and see how it goes, can you propose a feasible experiment to see how an new strict spec will measurably fail?
That... is not how anything happened.
> I don't see the same problem in other formats like JPEG or PNG where you expect the image to work perfectly or fail with a decoding error.
Browsers absolutely decode as much as they can, and if the file is corrupted halfway through you generally get garbling, not the entire image being replaced by "fuck off". The only case where that is so is if the browser can't parse anything at all, or can't retrieve the file.
> Other than implementing it and see how it goes, can you propose a feasible experiment to see how an new strict spec will measurably fail?
We already did that and saw where it went.