Never actually should have been "cut the PSD" it's just that artists under the DELUSION they were "designers" SCAMMED the industry into that sleazy mentally-enfeebled practice.
... and in the process came up with bloated, slow, inaccessible train wrecks of how NOT to build a website as a result.
Said delusion -- YES, I SAID DELUSION -- based on the fact that most such PSD jockeys had little to no knowledge of emissive colourspace (and the legibility issues so related), elastic design, semi-fluid layout, limitations of the medium, accessibility norms, or dozens of other concepts that separate design from art.
DESIGN involves specifications, guidelines, user experience. If the end result is useless to large swaths of users, costs more to host, more to build, and adds code complexity increasing maintenance costs, what good is it?
Hence why I don't think I've ever seen a website that started life in Photoshop or any other paint program that didn't end up riddled with accessibility issues that tell many users to go plow themselves.
You combine that with the general incompetence at HTML and CSS so common to the cookie-cutter front-end framework-using developers, and... well, just look at the hives of scum and villainy filled to the brim with nube predators like ThemeForest and TemplateMonster.
But again, Joe forbid anyone come right and say that; camel-mannered tunic-wearing mollycoddles...