I don’t personally like it. It measures input factors rather than outcomes. I think surveyed happiness multiplied by life expectancy is a better measure.
I would think that life expectancy is a poor metric, because: (1) the differences become smaller as it rises so it becomes dominated by noise, (2) it overvalues the last few years of life compared to the rest of a life, and (3) expectancy is highly dependent on how it is calculated along with parameters such as input factors, similar to those that you dislike!
In summary: intuition can often be a very poor substitute for research, and before relying on your intuition it is a good idea to look at the basics.