Why did they even bother to pan and scan movies back in the day?

[Coney]

The old tv sets had adjustment knobs. There was vertical knob to use when the picture would start to roll. Another for the contrast and still another for something else. If the reception wasn't good, there would be a lot of snow. Old TVs were hooked up to a big antennae to the roof. Not so easy to go up on the roof to move that sucker around. Rabbit ears came later. When color TV came out, the color was always off. There were knobs to adjust that too, make the picture more green or pink.

I HATED letter boxing. Our big TV was a 19 inch. Our secondary TV was 13 inch. Trying watching a letter boxed movie on a 13 inch TV with tubes.

TV repair was another big deal. The TV man would come to the house to make repairs, usually to replace one of the tubes. Those TVs were heavy, especially the ones that were in an all wood furniture cabinet. The would often share that cabinet with a radio and/or record player. How big can the screen be in a cabinet with other devices?

There are television shows now that make the "effects" of old TV sets, like snow or wavy pictures to indicate a flashback or a transition. Those look a hundred times clearer than the original ones.

A television was a fairly large expense from the beginning of TV through the 1980s. By the early 80s, they had those large projection sets and that would have been better at not cutting off movies as you described. But by then, the VHS and Beta formats were available and those projection TVs were very expensive and very heavy. Also TVs took up a lot of space. You couldn't hang them on the wall like now or even with one of those stands that attach to the wall or ceiling like they had/have in doctor's offices or hospitals.