The term is not being used incorrectly. The primary definition is now "underdeveloped countries" - because language changes over time. https://www.merriam-web

The term is not being used incorrectly. The primary definition is now "underdeveloped countries" - because language changes over time. https://www.merriam-webster.com/dictionary/third%20world https://www.merriam-webster.com/dictionary/third%20world