Some filmmakers kept this in mind when making their movies in the '80s and '90s. Films like Terminator 2 were shot open matte, allowing each shot to be framed for 4:3 and the target theatrical widescreen aspect ratio simultaneously.
I think these facts got lost on a lot of people who were die-hard widescreen LaserDisc fans. LaserDisc had twice the vertical resolution of VHS. And if you were a big enough moviebuff to have a LaserDisc collection, you probably also had a bigger than average TV.
The rest of these techniques, like colorization, seem more about making older content more palatable to newer viewers, and don't really do anything to solve a technical problem.