Well, some of us grew up here, so then there's the issue of "do I trade moving away from everyone I know to earn more money?".

Also, I'm not sure that everyone who makes the salary trade-off knows that they're doing so. Is a developer earning $35k/year thinking "I could earn more at another company, or in the Bay Area, but I like it here" or do they think they're earning a fairly average wage?

I would think that 'roots' would be a big drag on mobility in pretty much any city. So I don't know if that's a factor in Portland's unique 'problem'.

And someone who never thought to question their salary level is by definition someone who couldn't be conscious of any trade-offs that might be in play.

Is everyone aware? Almost certainly not. But if you ever had cause to look at salary data, I don't think you could miss it.

I've been told by jobs both local (in ND, not that it matters) and remote that my wages were being determined by looking at the local average of people with my job title. It would be hard not to know that your salary is scaled to where you live.

Another issue besides roots in moving is that higher wages always come with higher costs of living. I own a house where I live which has a lower mortgage payment, by far, than a small apartment in SF. Granted that comes with downsides: no decent curry, bars that can't make a manhattan, etc