The best thing you can do for your children is raise them in a home where the marriage is rock-solid and loving.
And that said, there are trade-offs and compromises and optimizing and multi-tasking and differentiating between need and want, all along the way, and sometimes the child’s needs come first.
If you carry it off with enough grace, your children won’t even know mom was putting dad first. And sometimes, there are circumstances and difficulties when all the grace there is - a gravely sick or special needs child - changes the family priorities, and that child’s needs do come first.
(BTW, I do wonder about those vacations for just husband and wife. Nice if you can get them, but if you have too many children, or a child with exacting special needs, it’s not happening.)
My husband and I got a vacation by ourselves (a weekend) when our oldest child was 22 and the youngest was 2.
On the other hand, my mother was able to spend several weeks in the Mediterranean when my father was deployed there because my brother and I could stay at our grandparents’ farm. I think I remember it more fondly than my brother does, but we certainly weren’t deprived of anything.