Is your developer salary also adjusted based on country per capita? Or are you getting a mostly Western salary?

Not the parent - it is definitely a better pay than other salaries in the country, but for example in Hungary a junior gets around like 2000 USD (per month) gross (and we have quite huge income tax here as well). Around 2600 USD it would be considered a nice senior salary.

Sounds like it's a better deal to just remain a permanent junior?

Steam does it very well for games, pricing games differentially such that they are much cheaper in 3rd world countries. JetBrains could do something similar too.

Developer wages too vary from country to country.

Steam basically turned it on for every developer until a lot of them noticed how little are they getting from some countries. If iPhones and TV cost the same I'm not sure why software products should.

If its a question of a little vs nothing, it is better to have atleast a little IMHO.

People in rich countries hate it when companies do that. There's also the additional hassle of verifying addresses. All so you can get a little extra money from some poor countries. I can see why they wouldn't bother.

JetBrains are from a low income country themselves.