Developed never really has the meaning that you think it has, imho. In Europe, during a long time, it really meant "like us" without thinking that each European country have a lot of different country. Looks at the difference in the Health system between Belgium and the Nederlands.

Actually the terminology shifted in some organizations as a continum of Low to High income countries (set by the World Bank). It is far from perfect but it frames the differences and terminology differently in your mind.