Earlier quoted context omitted.
You're totally correct when it comes to skilled work, they get snatched up when they've proven their worth. However, this cloud labor is for unskilled work. So yes, they are commodities, but if they are a lot of them, and a lot of work to go around, wages rise. We saw this with the industrial revolution, especially assembly lines. Mid 20th century you could live pretty well as an unskilled assembly line worker, but t…
These platforms make it easier to find labour and thus drives more competition between labour providers but they don't necessarily increase the demand for it, at least at higher pay rates. It also makes the competition for knowledge work go international which might increase pay in developing countries but lower it in first world countries.
Higher pay rates exist for two reasons, unfair monopoly positions (e.g. bill gates and the OS monopoly of the 90s, actors/athletes), and because there is complex work that hasn't been deskilled yet. Not much can be done about the former except regulations, the latter is where programmers can change the situation. Demand is everywhere - whether it's fulfilled by cloud labor, or by specialized labor - is the question.
Either way, I think we can agree that immense opportunities exist for startups to profit from this space.