> Digital tvs are cursed to wait for the next key frame in the video to start displaying

If they chose too, couldn't TV decoders pretend to have a all-gray keyframe as a starting point and apply the streaming diffs to that until the next true keyframe came? That would at least give some garbled image before snapping in. I'm sure most consumers would consider this "broken" though.

> Analog tvs would change in the middle of frames if you swapped channels.

They'd get a little confused, as the next vblank (and hblank) would come at unexpected times, as channels wouldn't synchronize frames.

> Digital tvs are cursed to wait for the next key frame in the video to start displaying

This is very annoying.

It doesn't need to be that bad if they cared about it. If channel is on the same band as previous one it could keep previous data in the buffer and decode it at once when switching.