Yes, I was replying to Bonny’s remark above mine. I quoted your original question, because her comment didn’t address it.
Yup, dealing with people, there’s always a risk. Trust takes a long time to build, but on these platforms, you got maybe a month. That’s why both sitters and HOs love repeat sits.
I’m not aware of any vetting processes, or procedures. I think most home insurance policies won’t cover theft by someone that has been invited in to a home, that would concern me as a host.