I'm not hearing a counter-argument. The company needs to get good people to work for them. And this is a way of getting someone from a high-cost location to work for them. If the location's higher living expenses aren't covered for, the person would be unable to take the job. I don't know if you mean that the company should adjust their lowest pay according to the world's most expensive location, but that would probably not sustain the business.
If the company finds a person that they want to recruit, and that person happen to live in a high-cost location, they will need to pay up in order for the recruitment to happen. The only alternative would be to offer relocation to a lower-cost region. It doesn't have anything to do with any requirement. It's just a result from the way the world works.
Given that most people aren't hired that way, it's more like:
If a person wants to work for the company but their offered salary isn't high enough to sustain a high cost of living environment, the person will need to either move or find another job.
The company has literally the entire world to find staff - that's the whole point of remote workers.
True. Still, I think most companies will take cost of living in the area where the potential employee lives into account. When thinking about it it seems odd, indeed. I guess it is kind of normal and expected. But entirely rational it is not.