The usual caveat that it's meant to measure a "hardship index" for companies relocating workers. I wouldn't use it as a measure for where to best move to as there are many factors it doesn't measure (such as how good the job market is, how expensive cost of living is, etc)- aside from maybe preferring cities in the approximate top (80+ out of 100), which is mostly "nice" cities in the developed world (no surprise there).

Assuming you're anyway not contemplating moving to Nairobi or Tehran I don't think this really gives much useful info as you can't really say you'd like life in a city with a slightly better score than another, it only matter if the gap is large.

E.g. I spent 8 years living in Vienna followed by 10 years in Berlin (a bit further below in the rating) and I don't feel my quality of life is at all lower here (I much prefer living in Berlin)- the main difference I notice is that Vienna is much better at cleaning up the trash from public spaces than Berlin, and a smaller city is generally easier to navigate.