If paying as little as possible wasn't that important to them, they wouldn't be hiring in Warsaw in the first place, but in the Bay Area, Seattle, Zurich, London, Sydney, etc
I've set up a small business with EU tax id over a decade ago and I'm issuing invoices to European countries (EU and Schengen) and North America.
It's a trade-off of giving up European employment safety, pension, some quality of life when working in different timezone, benefits and job security, to work for higher salary.
But it only makes sense until some business decides that they would like a contractor from Poland with a Polish salary.
Walk.
Any company that puts policy over people isn't a good company.
But you are right that this is not actionable.
With that said I tend to agree, most companies are shopping around for a bargain if they can find one.
Location-based pay in remote roles is a major red flag that the company doesn't reward merit.
It's much more easy to find an experienced tech lead even remotely, around London or SF, than say in some village in Bulgaria or Poland because no F500 tech company ever came out of there.
Companies like Google that have the infinite money glitch don't care about finding the best bargain employees, but most SW companies aren't Google.
What you do find a lot of in tech hubs is the type of people who move to tech hubs. This often means that in a certain type of company you get better "culture fit" by using a geographic filter (thus avoiding illegally filtering by protected characteristics), and you definitely get a higher percentage of people who are willing to structure their life around their career. And when you get enough of those people in a room together, they're certainly the types that will happily persuade each other that they represent "the best talent in the world."
Software is a potent leveler—all you need is a computer and you're on equal footing with the rest of the world—and I find that the best programmers are the ones who learned to do it for fun and only later made a career out of it. Those people are equally distributed across much of the world at this point, and if anything there are fewer of them (as a percentage of job applicants) in the tech hubs because the tech hubs attract those who chose software for the money.