You also asked about long commutes- people, in fact, do that. But if there was much better public transport systems available, both low and high wage people could commute a LOT easier. BART is great, in certain directions. But not down to Silicon Valley. And there's nothing significant in Seattle.
On the other hand, New York City has gone through this many times, and they manage to mix high and affordable rent places on a tiny island of Manhattan. The much more extensive subway there has done a lot to help, as have specific rent laws.
Heck, metro New York has always been massively crowded, and with HUGE wages, and somehow they are not nearly as bad as Seattle and San Jose.
And since New York has much less land and many more people, that kind of puts a lid on your argument, quite a bit.