Developed in "developed country" customary means certain things. Like a decent standard of governance, sanitation, education, healthcare, welfare and quality of life. All these countries I mentioned are roughly on the same level.

You don't have problems with access to clean water in Poland. You ain't going to die from hunger in Czech Republic. There are no issues getting education in Latvia.

And mythical Anglo engineering talent, please. They are approximately the same anywhere you mentioned.