You’re right that they either never learned what 1st-2nd-3rd world really means, or they forgot what they were taught in history class. Unfortunately it still is the main term to refer to poor countries even though it’s incorrect. Language seems to be biased towards the common meaning over the technically correct meaning.
No one really uses that word in its Cold War context anymore. It’s the common term for “developing countries” and the like.
People believe that only because they haven’t learned what it actually means.
You’re right that they either never learned what 1st-2nd-3rd world really means, or they forgot what they were taught in history class. Unfortunately it still is the main term to refer to poor countries even though it’s incorrect. Language seems to be biased towards the common meaning over the technically correct meaning.