"let's say for the sake of argument" is doing a fair bit of work here. But the point is that we had text editors (similar to the ones we have today) back when C

"let's say for the sake of argument" is doing a fair bit of work here. But the point is that we had text editors (similar to the ones we have today) back when CPUs were capable of maybe a few millions of instructions per second. CPUs can now do tens or hundreds of thousands as many instructions, but a text editor today uses several percent of that CPU. That would be like shipping a square kilometer of forest to the job site to build one house. The construction industry and modern cars could be more efficient, but their waste is measured in percent, not orders of magnitude.