If a well-earning programmer settles somewhere in a rural place, it means a) more money spent in a small community, b) one fewer affluent person seeking housing in an urban hotspot.
I would guess that the aggregated effect worldwide is an order of magnitude higher than whatever passes in Portland and SF.
The theory is good. Unfortunately, that downward pressure doesn't seem to be having any effect for cities in many western nations. Pretty close to runaway house pricing these days. :(
Ofc I had to lower my expectations with regard to good restaurants etc., but the resulting slack in our monthly household budget is enjoyable.
People will be unwilling to live in a small apartment or house in Ostrava the way they would in Prague so prices would skyrocket to beyond unaffordable very quickly.