The frame is a compositional aid, and it does have quite a strict relation to what the camera is capturing.

The best version of your complaint is that the viewfinder does not have accurate frame lines that account for parallax at various distances, which is true, but there are still ways of using the viewfinder to assist in composition.

If you take two or three shots at two meters, and look at what the camera captured versus where your composition was in the frame, you can immediately intuit a baseline for where the frame lines 'should be' on the viewfinder at two meters. "Occupies the bottom right two thirds of the viewfinder" for example.

Without a reference frame, these intuitions (and your aiming of the camera!) are going to be far less accurate.