The GP is pointing out that storing an uncompressed film isn't useful if it can't be played back. Playing back an uncompressed 4K film is nearly 600MBps. That's a data rate you're not going to get out of any consumer HDDs.

To elaborate on this, higher frame rate video registers the same way to people who aren’t aware that’s what they’re noticing. I was discussing this with my dad just a little over a week ago, where he noted some portion of a movie looked lower production than the rest of the movie. I had noticed it too, because it was visibly higher frame rate. Lower frame rates more closely match the visuals of film, and higher frame rates more closely match the production of daytime TV like judge shows and “soap operas”, and that’s what they visually evoke.