But with the changing nature of computer programming, arguably programming becomes more efficient and needs less manpower. It's easy to see that programming a web app today takes less man hours than it would've if you were to try to do it 30 years ago using C.
So far it seems that these efficiency gains have been offset by growing demands in what software can do, making the industry continue to grow. I wonder if at some point in the future, these demands will stabilise and continued improvements in efficiency will necessitate a reduction in the workforce.
Will automation make a computer programmer's job disappear? No, probably not. But will it allow one person to do the job of ten? Maybe.
You'd have had a hard time coding the web 30 years ago, given that it hadn't been invented yet; but 20 years ago, Perl was about as productive as something like Python or Ruby today[1]; a web server, after all, just provides stateless RPC. What was missing was a lot of frameworks that could permit a developer ecosystem to grow, a developer ecosystem being something that lets your more easily reuse things other people wrote. Developer ecosystems with critical mass are what increase productivity, rather than technological improvements.
[1] Technically, I think common web frameworks aren't particularly productive, because they are built around a very low common denominator. I worked on a CRUD app framework in the early 2000s that would still blow something like Rails out of the water in terms of productivity.
The history of computer programming is the history of people trying to automate computer programming. All that ends up ever happening is that the nature of computer programming changes.
Just think of all those assembly-language programmer jobs that were "automated away" by the invention of Fortran. Or all of those C++ programmer jobs that were "automated away" by Java, Ruby, SQL, whatever.