This is of course because of outsourcing. Junior devs usually do repeatable tasks guided by a manager closely, which is exactly what outsourced heads can do, definitely cheaper than the junior devs in the U.S. would. This is normal.
Outsourcing destinations, because there is little demand for senior outsourcing heads. They become harder to manage, and their jobs are high impact enough to justify the expense of hiring them in the Valley directly.
People who outgrow junior level will just make their own startups, or move to U.S. from the locations: outsourcing shops won't need them; more: they will take conscious effort to prevent them from ever growing, because growing, they become threats to these body shops.
