Living in Western Europe is substantially more expensive than America in my opinion. I’m not sure Americans retirees are ready to trade-in their roomy houses for a small flat in Europe. Plus Americans are foreign language averse so the only places their could live are Ireland, the UK, perhaps the Scandinavian countries, Germany and Switzerland. Those countries are too cold and dreary in the winter.
By comparaison, you could buy a house in areas of America (Florida, Georgia, Carolinas, etc..) for $100k.