In response to that I will take quote "Only Dead on the Inside" by Author James Breakwell

"A minivan has room for luggage. It has room for air. And it has room liquids. That's right: It has space for THREE states of matter. Kids shoot liquid out of every orifice, and it constantly needs to be replenished. The minivan knows that it knows everything. Each minivan has at least twelve state-of-the-art liquid stabilization chambers, known to commoners as cup holders. That's way more than any other vehicle. It's basically a cup holder collection with an engine attached. If you want to you can haul a dozen slushies at once. Can't find slushies at the end of the world, not my problem. I don't have problems. I drive a minivan."

More seriously, when we go to visit family you can't fit luggage for a family of 5 and that family in a Camry, also when you have to grocery shop with 3 small children you have to be able to fit both the groceries and the children in the car at the end.

I agree that 3 children is way different than 2 depending on age. Just think child seats (i.e. trying to fit 3 in the back seat of a regular sedan will be a challenge, while it's completely possible for 2. Been there, lived that without any issues.

For luggage (even with 3 I would think) a hatch back does wonders. My larger limousine cannot fit the same amount of luggage or larger packaged purchases, simply because it doesn't fit through the trunk door at all, gets stuck because it's too long or too high and gets caught by stuff that sticks down into the trunk space (why they designed things that way, do not ask me). All of those things fit into the smaller hatchback we have without any trouble at all.

I can count the number of times I have had to put something in the rear seats for groceries on one hand and that was w/ the "large" car where I combined toilet paper, kitchen paper and a 'large' Costco run and the trunk space itself could've fit everything if it hadn't been for the above mentioned problems that would have been solved w/ the hatchback. 3 children on the backseat would've been no issue in the hatchback in that situation. Now going through a Costco on a busy Saturday morning w/ 3 small children would've been another story ;)

Have you ever tried installing 3 car seats into a compact car?

There are some expensive car seats designed to cram all three kids into a back seat, but buying a larger car instead is cheaper. They also tend to be designed for triplets, if all three kids are different sizes it becomes a lot more complicated.

Most cars only have attachments for two car seats in the rear, so even if you did have space the middle seat would have to use the generally discouraged seat belt install instead.

Right, that's my point in responding to the parent comment about fitting 5 people in a Camry; it's not so simple when 3 of them require car seats.

We have a 7-seater for extended family. My nephews come over a lot, so that allows us to transport all four children, two to three adults, and a small amount of shopping bags or picnic supplies.

The fuel efficiency isn't great, but that's why our primary vehicle is a sedan that seats four (plug-in hybrid). Generally we use the sedan, except for large shopping trips or when needing the larger seating capacity.