"dev", "designer", "manager", etc. aren't interchangeable machines in the same way that compute instances are; they're human beings! Would you personally work for this "AWS for employees", with no job security, with no consistent working relationships with other people, with no knowledge of why you are doing the things you are tasked besides "the algorithm said I must do it, so I do it"? I know I wouldn't.

Fortunately, this is a horrible idea that has essentially zero chance of becoming reality, as things like stable work relationships and a sense of purpose boost productivity, making employees more productive per unit labor cost than a Mechanical Turk for making more Mechanical Turks.