I have purchased 6 multi Tb external drives at estate sales. My son brought home a few from a summer working as a mover. In his experience it was divorcing spouses throwing out each others stuff.
All of these drives had Pii and personal photos. Some of the estate sale drives included pii of children and grandchildren.
I've found a few cheap hard drives at thrift stores. I used to buy them just in case someone had left a crypto wallet on them.
They're usually formatted but not wiped, so even recuva was typically able to claw back all of the missing data and restore the whole drive.
Family photos, nudes, sex videos (homemade and professional), downloaded movies, pirated games, I've found them all.
If you're dumping a drive and you don't DBAN it first, other people getting to see your shit is 100% on you.
You left out the most interesting part - did you find any BTC?
No, I would have included that otherwise, lol.
I feel like there's other solutions to protecting your and your family's PII than encryption by default.
Could you share them?
Not selling drives without securely wiping the data, for starters.
"What about unhappy exes?" Well if they really care about the kid and know the exact spouse is techy enough, they'll put their ego aside for the kid and ask their ex to do it.