According to the 2019 census, Luxembourg's population is 615000. Of this, roughly 292000 (47.5%) are foreign nationals living in Luxembourg. Luxembourg is unique in many ways and is also one of the friendliest countries on the planet for expats. Let's look at some of the reasons that make Luxembourg so special.
Bureaucracy is welcoming: First and foremost, the first touchpoint before moving to any country is its bureaucratic system. Interacting with Luxembourg's bureaucracy for visa and relevant topics is welcoming at best, and respectful at worst. It would not escape an expat who has tried the same with other countries, how much feeling respected by the bureaucratic system makes a world of difference. Think and come-up with countries that make you feel the same, anywhere in the world and you will know what it means.
Expat population are educated and earn well: Most of the international population in Luxembourg work in international contexts. They are either working in the private sector (Amazon, BIL etc.) or at the European institutions (if you're a European expat). Most of the expats are rather well-educated, most likely have lived in another country other than their home country, are open-minded and have good earning potential. This translates to many advantages: better public discourse, high quality of life, and higher security to name a few. This is good.
Pollution levels are low: According to the Air Quality index, Luxembourg ranks 83rd and ranks better than many leading countries including Germany. While most don't think pollution is an important criteria in our migration decisions, nonetheless there are real benefits in terms of saved time and pain. Again leading to higher life quality. https://www.iqair.com/world-most-polluted-countries
Nature: Seeing green plants, trees and experiencing the wind, rain and sun is no longer a standard in many cities. Make no mistake, its a luxury. Luxembourg has nature all around. Expats walking around in the woods, running along the river and taking a stroll in the valley are common sights.
Opportunities abound: While the industry diversification in Luxembourg are limited to few such as Finance, legal, administration, technology infrastructure etc. Nonetheless, Luxembourg manages to create value, adapts quickly and offers opportunities for building a life-long career in Luxembourg. Yes, there are tons of people who have worked and retired in Luxembourg.
Luxembourg appreciates the value of expats: Luxembourg is a knowledge-economy based country. That by definition attracts certain levels of expats to the country who have better opportunities. The competitiveness of Luxembourg, and the value of expats to the Luxembourg economy cannot be understated. And importantly Luxembourg recognises it. There is no reason Luxembourg's real-estate price should compare to that of Paris and London if not for the competitive economy Luxembourg has built. So, there is mutual appreciation: Expats appreciate the opportunities and Luxembourg appreciates the expat community for its contribution in keeping Luxembourg competitive. The mutual symbiotic relationship is the key for the expats' success story in Luxembourg.