I see, you didn't get what devaluation mean. A currency has relative value because ppl buy goods in global markets. When birr falls from 29 to 160, a Dr’s salary dropping from $340 to $75 is lost purchasing power. Countries don’t live in a vacuum, he buys medicine, fuel in $
Using currency as a measure of economy is not a fair even a logical comparison. Example 1USD is 159.47 JPY but it is 15 Eritrean nakfa so taking your logic Eritrea is in a better place economically than Japan.