> software is very easy to get duplicated and commoditized.

Software engineers are not required to copy files around. They are hired to figure out what is the best way to deliver the features envisioned by product managers, and how to keep things working.

> So the margins get tighter and tighter and companies with "finished software" will have less and less money to be collected.

There is no such thing as finished software. At best you decide to stop maintaining it.