In the past, many people believed that 4K TVs were a sales gimmick because it took more than seven years after their 2012 introduction for 4K content to become available in any respectable quantity, and then mostly on streaming services such as Netflix and Prime Video. Even when 4K content was viewed, many people found little difference between 4K (2160p) content and 2K (1080p) unless the screen was at least 65".
There Was Only One Way to Tell
The only true way to determine any difference between 4K and 2K is to have identical content running on both types of TVs side-by-side. Unfortunately, this is no longer easy to do if not downright impossible. Such a setup would only be found in stores selling high-end audio/video equipment, and large-screen 2K TVs are practically obsolete. Nevertheless, scam or not, millions of people love their 4K TVs no matter what the size of the screen. See 4K TV