Every useful quality of life metric shows that men are happier and live longer if they are married to women

This is a measurement of who women choose, not of what affect women have. Women choose to marry - then choose to stay married to - men who are "above" them. Men who are taller than them, who stay up later than them with energy, who aren't significantly affected by the womens childish emotional tantrums.

Naturally these kind of men would be happier and live longer regardless of whether women were around or not.

while the reverse is true for women

I suspect it's their usual trick of defining "quality of life" in male terms.