My parents moved into separate bedrooms when I was 6. My mom moved out when I was 10.
It was an incredible relief for us children. Not because we hated her or anything.
But the fighting stopped. Both of them stopped drinking daily. The constant, tense atmosphere at home was gone.
We continued living with our dad, but spent most of the day at our mom’s place 3x a week.
Weekends were usually spent with both parents. Because since they weren’t forced to live together anymore, they actually got along very well in a friendly way.
Later we celebrated big holidays together with my parents AND their respective new partners, and my mom was present at my dad’s second wedding, as was her new partner.
It probably doesn’t work out like that very often. But your children feel when a marriage is only sustained “for their sake”, even if they aren’t conscious of it and can’t put it into words. So separation can also be better for them.