Every sedan bro think sedans are justified. And they trot out all the same points you just made.
I offer you challenge: count every sedan you see, and record whether or not it has all seats filled. I actually did that for a month, and its literally below 1% usage.
That's what you sound like.
Yes, too many people have large trucks that don't really use them for their purpose, but some of them are not that different from a sports car or sedan when not hauling a load for mileage and shouldn't be expected to be used 24/7. SUVs are probably worse overall than trucks when it comes to excess unused space and mediocre mileage, but nobody complains about those.