Subjective. Irrelevant. Dependent on what criteria you use to define "quality of life". Different criteria = different conclusions. Opinions are not facts, and anyone can weigh value differently to control the outcome.
Example:
If Nation 'A' has more qualities than Nation 'B' of what a particular individual places the greatest value on, that individual will naturally consider Nation 'A' to be superior to Nation 'B'. However, a different person might place higher value on different qualities, making Nation "B' preferable to Nation 'A'.
You clearly put a higher weight on single-payer healthcare, and wealth redistribution than I do, so nations which do that will always rank higher in your evaluation. I have a preference for liberty, a market-based economy, and merit-based preference, as such I will always tend to rank those nations higher.