If you've got 4 kids all under 4yo, you're kind of screwed no matter what vehicle you drive. For biking, you'd probably be looking at a Bakfiets with electric assist plus a trailer.
Presuming we've sufficiently eliminated car traffic and the roads are safe for kids, it's also likely that at least one of those kids can bike themselves to the store with you.
4 kids will fit after everyone has been dressed, got their shoes on, got their shoes on again, been lifted/chased into the car/bike. That's what I meant by "screwed". The choice of vehicle doesn't really matter.
Once they're older, kids can bike themselves or walk. Families also manage that.
I don't see how you managed to see something like that as condescending or condemning your family choices. It's just a problem that parents with four children presumably have to deal with?
Funny enough, I saw a mother of 4 biking today in Boston. It was raining and 50F/10C outside. She had a bakfiets with 3 onboard and a kid pedaling behind her. I don't think they were going grocery shopping though.
Presuming we've sufficiently eliminated car traffic and the roads are safe for kids, it's also likely that at least one of those kids can bike themselves to the store with you.