Yes, this means there are many engineers in SF that are actually/currently paid MORE than they would be in an efficient market (and there are many software developers in developing countries that are paid LESS than they would be in an efficient market). Right now there's enough money going around that nobody cares about market efficiency, but if we have an actual, deep recession in the sector, I expect all the music to stop (and the efficiency of the developer market to go up on the whole).
In software we can pretend to ignore these discrepancies, but it becomes patently obvious if you've ever dealt with international companies who discriminate based on nationality for people doing the exact same job (and not in software, where you can argue talent - literally the exact same job - two performers doing the same act in the same show. I've seen pay discrepancies of up to 2.5X or more for an American Expat in Hong Kong and a worker from the Philippines, for example). It's all about what your individual alternatives are.