alt Hacker NewsDepends on distance and size, there is a lovely chart. My projector at 10 feet away is night and day difference at 4k. Mathematically 8k should look identical, so I haven’t spent the money to try it to confirm.
The 1080p thing is true in the age of 40” TVs but not so much now, think Costco has a 95” TV if not 100”.
I can definitely tell the difference between 1080 and 4k on my 55inch at around the recommended viewing distance. Less so on a 42 inch. A 4k image will look good even on a projector, as you say.
Personally I think 4k (with HDR) is good enough for consumer use, so agree with the parent theoretically just not quantitatively.
It did take around 20 years from DVD to 4k Bluray though.