Such grouping is based on dubious theories. For example, China is classified as a "developing economy" (red), even though it is one of only three countries with the independent capability to send humans into Earth's orbit using its own launch systems and spacecraft.
Only because their population is so huge. Their Dollar GDP is about 2/3 that of the USA and is 4.5x that of Japan. In a sense it’s set of highly developed urban industrial zones that also has a massive underdeveloped rural area.
GDP PPP is being used to compare countries productivity more often now. Australia has high GDP but low productivity as most is sunk into expensive, unproductive real estate. Every country has their rust belts and undeveloped rural areas.
Sending humans to orbit while leaving millions of other humans starving on Earth is not a sign of great economy. China undoubtedly made a lot of progress in recent decades, but it also started from a very low point. Its GDP per capita has improved greatly but still way lower than most Western countries.
