Earlier quoted context omitted.
To put that in context, when my grandparents were born, a typical family had around four children, and one in four children did not live to the age of five. It is sort of crazy to think of what it would be like to grow up in that world.
I think a modern USA 1 year old has about a 99.97% chance of making it to adulthood. That means that if a modern USA adult loses a young child, there's a decent chance they don't know anybody who has had that experience. The ancient (and even, as you point out, very slightly pre-modern) world had a lot of "infrastructure" in place to deal with this, there were rituals and ceremonies and familiar people who knew what…
But you're right, it's far harder to go through an experience alone, and loss of a child has certainly become far, far less common than it used to be. At least, if you limit it to the born.
In the US, in 2023, 1 in 3 never made it to birth.