Sure they can: They can have the grandparents move in with them and take care of the kids. Just like in the 19th century.
Of course, Americans simply refuse to do that.
On our national tombstone, it should say, "Can't someone else do it?"
I kinda like this one.
"Yes, you've been pampered, cosseted, doted upon, helmeted, bubble-wrapped," McCullough said in his speech. “Yes, capable adults with other things to do have held you, kissed you, fed you, wiped your mouth, wiped your bottom, trained you, taught you, tutored you, coached you, listened to you, counseled you, encouraged you, consoled you and encouraged you again. You've been nudged, cajoled, wheedled and implored. You've been feted and fawned over and called sweetie pie. ... But do not get the idea you're anything special. Because you're not."
19th century? I must have had a time machine growing up. My mother's parents lived with us and raised us inside our home in East English Village. Brother's a cancer doc. I'm not as smart but I'll be ok.
I think Americans will be fine, though I agree with your "Can't someone else do it?" comment. We're like that magical 3rd and 4th generation of wealth...the ones who witnessed none of the wealth creation, none of the wealth amplification, and all of the wealth consumption.
We have met the enemy, and it is us.