The problem with punch holes is the fact that a portion of the display is missing, being replaced by cameras and/or sensors. Hence, that part of the display is inactive, pretty much like in the case of notches. Where there’s no display, there will be no content. Samsung is apparently working on fixing this problem. Whether it will be a secret Galaxy S10 feature, or we will have to wait until the next flagship is announced, is yet unknown.
A recent patent filed with WIPO (World Intellectual Property Organization) was uncovered and it describes a smartphone with a secondary display area. Its sole purpose is to prevent the punch hole from not displaying images, or, to make use of the punch hole and make it display something.
It would be a transparent display area that can be used to display icons, animations, or other relevant graphics. These might include camera aperture animations, heart animation for fitness and biometric operations, and even rings around the punch hole camera, like in the case of the Galaxy A8s.