Actually median also a not good metric when power laws are involved. For example, if half of the country is living below poverty line then you being above media

Actually median also a not good metric when power laws are involved. For example, if half of the country is living below poverty line then you being above median still doesn't mean you have comfortable lifestyle. Tech people are often told that they have top 10% of salaries in the country but when you look at most of their lifestyles (i.e. below 1%), they are living in cramped apartments, doing 2+ hour commutes, reluctantly sending kids to schools they don't like etc etc. When most of the people in country have minimum wage below $10, even median would be pulled too low and that is one reason poverty line is defined such a way that these people don't come under it.