Reality is not like your linear thinking & baby math. Growing economy is like climbing mountain. You

start from low altitude and it's easy, you may spend 4 hours and climb 2,000 feet. When you reach to high altitude, it becomes more challenge (steeper). You may spend 5 hours for 800 feet. You can't use linear algebra to compare low altitude climbing and high altitude climbing. Same applies to growth of developing countries and developed countries. Many developing countries have better number in term GDP growth than developed countres' . But you can't say economy of developing countries is better than that od developed countries based on your baby math