Just as an update to this for anyone who cares, in taking out the remains of the shelving I discovered that the position of the crossbeams is adjustable, and they could’ve been shifted over and screwed into the wall studs. Instead they used more split-style drywall anchors.

That said, it looks like there were some parts screwed into the wall studs: three small hooks made of a different material that finally snapped after however many decades of use. Amazing that only three of them held it up for that long.

I swear, the replacement shelving is going to be so overdesigned…

How much is it gonna be to repair it all now?

This happened to me when I bought my first house. Came home to clothes all over the place due to cheap plastic anchors. So annoying to fix, and a sign of other problems to come. Lazy contractors gonna lazy

They can be mounted on drywall… with anchors

My parents bought a house a couple years ago, and the previous owners thought it would be okay to put a wall in by screwing 2x4s into the existing drywall of the adjacent walls and putting the sheets up on either side of the 2x4.

They also thought that nobody would notice the fresh paint and fresh plywood used to cover up massive amounts of mold, and when it was discovered after the first day they shrugged and went “oh we had no idea” and a judge believed them.