Now, why are the jobs there? Is it because everyone wants to pay tons more for housing, or is it because people with higher incomes are willing to pay for better living conditions and everyone else is pulled along? Tech didn’t used to be anywhere near this concentrated but over the decades people moved out of declining cities and that produced the current hyper-concentration. That cycle is brutal - you have cities like Rochester which have a lot of comparatively cheap real estate but until the senior management want to live there, they won’t have enough businesses for any skilled workers not to think they’d be screwed if their current employment changes because there aren’t many alternatives.