Mechanical Turk is generally used for things that machines still can't do with nearly the accuracy that humans can. Image recognition, facial recognition, translation, dictation, etc.

No matter how much hardware you throw at those problems, you can't (yet) match what a human brain can do in a split second. I don't think that's depressing.

Cheer up. People are not cheaper than machines, they're just better at some tasks. You'd have to complete tens of thousands of those stupid little tasks to pay your rent for a month...if they could be done by machine reliably, they would be.