[James2001]

Even SD content usually looks perfectly fine as long as it's handled from a decent quality source and doesn't have any processing or filmising added to it. People have got so used to YouTube videos, stuff that's been converted to 25/30p on streaming services and material sourced from VHS (or had fake VHS filters applied) that they think old TV looked a lot worse than it actually did. I remember talking to someone around a decade ago who was working on a programme which gave him access to a master tape of a late 90s Blue Peter and that it almost looked HD when you see from there without any broadcast or compression related artifacts.

Same with black & white TV, as so much of it only survives as not brilliant quality telerecordings covered in dirt and scratches, people think that's how 50s and 60s TV looked (and what you often see when programmes try to emulate the look of old TV), when it would have looked a lot cleaner and sharper originally (the few surviving 405 line VTs show that).