This map is somewhay misleading, some countries use currency without decimals, making their currency worth effectively less. Take for example the euro, a cent (a one hundredth of an euro) is cerntainly worth less than a robux while an euro isn't. The same comparison with the japanese yen (efectively a cent) shows that robux is more valuable. The map should be how many robux can you buy with the minimum wage for example.
The point of the comment is to point out the common misconception that the value of one [token of a currency] has anything to do with the strength of a currency. As described in the comment, the value of a singular token of a currency can be chosen arbitrarily.
This, of course, doesn't mean the map is factually incorrect.
This map is completely meaningless. The local value of “one money” in each country’s currency varies massively. A Coke might cost 1 dollar in Australia but cost 1000 won in South Korea, but Australians make 50,000 dollars per year while South Koreans make 3,500,000 won per year.