The idea that software development will somehow become obsolete because there are open source programs freely available is a fallacy. It is like when 20 farm workers are replaced by a mechanized piece of farm machinery, they don't just starve and die. Those twenty farm workers end up operating, repairing, and building those pieces of farm machinery instead of breaking their backs in a field and every benefits from the productivity increase.

Software is similar. There's no less money being thrown into technology now than there ever was. The difference is that instead of throwing all their money on basics like OS and Office suite, now they spend your money on more complex things, custom internal software, employees capable of managing and aggregating FOSS, and highly complex systems that have not been tackled by the community. This is great for programmers in general as there will be less drudgery, more respect, and more rewarding work than have existed in the past.