Yeah it's really gross. My mom and her husband - just the two of them, no kids, no pets - moved out of an 1800 square foot house with a garage and basement because it was "too small for them." They had storage units for their excess junk.
Now their place is about 4500 sq ft, with a full sized basement and two car garage. It's packed to the gills. Every drawer you open - full. Every flat surface - covered in things. Not hoarder level, it's somewhat organized I guess, but it's just shit. All useless. You could toss literally 95% with no loss of convenience or living quality. Everything they own, they own 4+ of.
Same deal with my girlfriends brother. Two kids, and they spend a fortune building this beautiful modern minimalist house - laboratory looking kitchen, custom interior glass doors, polished concrete floors. But it's FULL of toys. Every single floor of every single room is just overtaken with kid shit, none of which the kids care about whatsoever.
Not to get all sanctimonious but I live with my girlfriend and cat in a 275 sq ft apartment. I can cook any meal, I have one shelf of books, two sets of sheets, and exactly one of every item that I really need. Every time I buy new thing I find an old thing to toss. There's no shit hiding under my bed, desk, couch, or anywhere other than my closets. It's a good way to live, I like it.
But yeah, the discount culture has made a lot of people into semi-hoarders. Very anxiety inducing lifestyle.