Don't you have kid(s)? I really don't understand how anyone with a child older than a toddler fits in anything like that. FSM help you when they start doing sports and there is constantly shit and dance bags and everything to carry around.
The phrase "necessity is the mother of invention" comes to mind. If you've always been able to afford more car than you need, you've probably never had to spend any brain cycles figuring out how to make it work, but that doesn't mean that it
can't work. If there are reasons to have such a small car - such as a limited budget and/or living in a city that is not suited to land barges - one
can make it work.
As I mentioned a few pages back, I can offer one data point that two adults and three kids (aged 10-15 iirc) driving about 2,100 miles to southern France and back, in a 1998 VW Polo. That's a car 1.7m wide (5ft 5 in) and 3.7m long (12ft 2 in) long (and iirc a 1.2L engine). I'm not kidding when I say that there exist golf carts longer and wider than that.
Comfortable it probably was not, although I can't say I remember the trip terribly well, so clearly it didn't leave traumatic pyschological scars. I suspect I spent the majority of the trip either reading or asleep - I was the little kid in the middle, acting as the demilitarised zone keeping the older two from declaring war.
Edit: to be fair, that was also with 1998 safety expectations, so, e.g., no side airbags, and with kids out of the armoured escape capsules they're expected to have these days.