Like acoustics make things sound good, it's honestly really complicated and hard to get right.
Having shit everywhere prevents noise from bouncing off things.
The confusion is probably because recording booths are sound dampened. That's not to make the record sound better, it's to isolate everything else so that the mix can be clean and prevent echos.
A good echo is literally what people stereotypically look for to gauge the acoustics of a space.
I guess it partly depends on what all is being hoarded. If by chance it's piles of clothing, then I guess it would double as pretty decent sound dampening.
But if it's a bunch of glass and/or metal stuff, well yeah that wouldn't work very well at all would it?
Trust me on this. We've tried to intervention some relatives repeatedly, their house is a terrifying example of fire hazards X man-trap stacks of:
national geographics 1910-2007
rare glassware
collectable books
TINS! Tin signs, tin trays, tin toys, tins with sewing shit and tins which held sewing shit in the triassic
radium! ?!?!?!??!?!? specifically clocks that are known to have been painted with radium that no longer glow, but apparently the glow - came from the overpaint, and the radium is still chugging. no shit.
newspapers, specifically, about easily tens of thousands of the dallas morning news 1990-1998 (!?)
multiple stacks of other newspapers (old stuff) one of them paid to purchase.
multiple layers of unopened ebay and amazon orders in the fucking boxes
CREEPY FUCKING DOLLS
A ROOM ENTIRELY FUCKING FULL OF CREEPY PORCELAIN FUCKING DOLLS
I swear, their eyes just swiveled to look in my direction from 12 states away.....
I can't even begin to fucking deal with this shit from across the country, and their relations in-town have so far failed to get through to them.
I'd say the acoustics would be pretty fucking bad.