My parents own an epic amount of mostly useless junk. But they also have an enormous house with a storage room in their basement the size of my entire condo. Actually, bigger. The useless stuff is all in the storage room. It is neatly organized into bins. None of it is gross or unclean, but most of it is of questionable utility. The storage room has no other possible use; their home is already way bigger than what they need. There's no reason to keep all the crap, but there's also no good reason to throw it out before they die either (they'll pay pros to schlep it all out either way.)
If I kept that amount of crap in my condo it would be straight up hoarding, since there wouldn't be space in my condo to move around! But for them, it's roughly proportional to the one closet in my condo that has old cords, some left over paint, sentimental books from grad school that don't fit on my shelf, my wife's wedding dress, etc.
If I kept that amount of crap in my cabin it would be a that weird mid-point where it's not quite hoarding but also taking up a slightly unreasonable amount of space.
Based on decades of sampling, Manhattan "fucking gross throw your old shit away" very much is midwestern "totally normal amount of stuff in basement storage". The price of storage does matter and we're talking about a range from $1/sqft to $2,000/sqft. Storing extra wrapping paper you got on sale at $2k/sqft is insane. Storing them at $1/sqft saves you a 20 minute drive to the store during holidays for the next few years.
What technical term? "hoard" is just a word. It becomes a technical term if you say "compulsive hoarder" or "garbage hoarder". Those are symptoms of a condition such as ADHD or OCD.
It's not “hoarding” until it crosses the dysfunctional line. This is the problem with using technical terms in nontechincal discussions.