in 3 to 4 sentences mention one disadvantage of using real gdp per capita as a standard of living measurement

GDP does not account for quality of goods:

Consumers may buy cheap, low quality, short lived products repeatedly instead of buying more expensive, longer lasting goods. Over time, consumers could spend more replacing cheap goods than they would have if they had bought higher quality goods in the first place, and GDP would grow as a result of waste and inefficiency. eg. China exporting cheap and worst quality goods all over the world and other countries are showing fake GDP numbers and not saying a word against China.

Even the gross domestic product is a very good economy production measure, it is not a very good standard of living measurement because if we compare two countries and one has higher GDP than another, it may seem that it has a greater welfare; however, this is not at all like because we are not considering the population of each country and their individual incomes and how are distributed the ones.