For instance, in 2003 there was no such thing as a mobile phone; passing code review today is probably going to entail either being responsive, or directing to a mobile version when accessed from a mobile device.
Okay, I will clarify my hyperbole in the face of the pedantic - mobile phones did not provide ubiquitous, standardized approaches to browsing the web, such that UX guidelines for the web did not include them; media queries and such did not exist except as drafts, etc etc.
