True, it’s the law of one price. However, privileges / capabilities aren’t evenly distributed. So, while remote does widen the labor market, wealthy countries tend to carry large shares.
It’s not a zero-sum game at all. Employees from wealthy countries can gain labor surplus through technology transfer a number of ways or even find business partners and employers.
Mutually beneficial exchange is the name of the game. It’s true that different folks achieve different relative success compared to their peers. That’s okay and good when it’s the product of honest just exchange.