I think in many cases it is more likely that said companies that you worked for would have zero developers without open source software. Open source has enabled companies, who otherwise wouldn't be able to afford to enter the software game, to take on programmers themselves.

You were perhaps able to do the work of 4 developers, but if 10 new positioned opened across multiple companies like yours due to the same effects it is still a significant net gain that has only helped contribute to shortages and rising incomes.