The higher quality-of-life was likely true at one time but I think it is quite arguable now in much of Europe. There is a palpable sense of decline that weighs too heavily on everything. How "quality" is a life without meaningful optimism for the future? It is the quality-of-life of a pensioner waiting for the graveyard.

An underrated benefit of the markedly higher standard of living in the US is that people can choose to trade standard of living for quality of life if they wish. American culture seems to preference maxing standard of living but that is optional, and there are plenty of people that make other choices.