What is this part I found on the floor

Be sure to check all of the cabinets and compartments. Anywhere that has a gas strut.

There is no marks around the holes, which suggest it was never mounted, so it would seem it was dropped and never picked up.

I believe you nailed it.. Now the question is did it come off the bed, or was it dropped in the camper and not picked up. I'll have to run over to the storage unit one evening and see if the bed struts are all connected.

I drives me nuts to spend a bunch of money on something, and it is assembled so sloppy. Just stupid stuff like screws not all the way in, and others stripped out.

We had a Popup for 9 years, and the only thing we had that messed up, was the plastic hinges on the dinette lids.

Apparently it's not just $30K RV's that have issues. I know of a couple who purchased a $1,000,000+ class A and they say it took them over 2 years to work all the bugs out of it.
These kinds of stories don't say much of Quality Control.

That is a bed lift support bracket. it holds the gas charged lift supports under the bed. and you will be finding things for a year, they drop stuff and leave it. nothing like attention to detail when you are building a $30k RV!