Parents say this, but looking at their lives and talking to them, it doesn't. I think you just get used to it, or develop a sort of stockholm syndrome.
Maybe you sleep a little better so it's easier to mentally cope with it
Nonsense. As a parent of an 8 & 10 year old, I'll emphatically disagree with you here. It 100% gets better - every year, they're more fun and more independent. Talk to any parent who's kid has just left for college and the vast vast majority of them actually feel overwhelmingly sad when it happens.
No, it does get better. The first year is just constant lack of sleep and disruption. As they get older they get more entertaining and need less constant attention.
One perspective that helped me was "little people, little problems". In few years they might be drinking your booze and stealing your car.
Mine are five and eight now. There's still rarely 15 minutes. Somebody's hungry, somebody's hitting somebody, somebody's having another meltdown.
On occasion though, they get interested in whatever I'm doing though, so that's nice.