Indeed, most of my daughter's friends in early elementary school lived with their parent in a 1BR, studio, or a rented bedroom. One of them had 3 siblings, making 5 people in a 1BR apartment.
I guess maybe parents had fewer expenses when I was a kid (I was born in 1983)? No cable bill, no cell phones, fewer video games, no streaming services?
IIRC, housing, child-care (especially if you include after-school activities), and health-care (If you are un- or under-insured with your job) dominate the increased expenses. Housing is a strange one because a lot of parents will try to move to a better school district, so parents may end up paying more for otherwise similar housing than non-parents.
FWIW, the things you give as examples are rounding-errors in our budget (though only two of our kids have cell phones so far); we don't have cable, pay $22/mo for streaming services, buy used video games, and pay an average of $60/mo for our phone bill. We spend over $300/mo on groceries for comparison.