you think that is the key to happiness? Many of my married friends with kids would tell you otherwise.
Typically my life is at a solid 10, I've done more and accomplished more than I really ever expected to, everything at this point feels like a bonus.
I don't give myself a 10 now because I recently moved and am dealing with moving in, home repairs, and my GF moving in with me. More challenges than I had originally anticipated so it throws me off my game from time to time, but life is still really good, far better than average.
I don't think a marriage with kids is the only key to happiness but your friends sound like terrible parents or stuck in a bad relationship. Maybe I'm taking your post wrong but there's really nothing else imo if you've got healthy kids and a good wife.