I think it’s pretty doubtful. If you do a search on the forum, you’ll find there are a number of “nomads” who may not have a permanent address but are far from “homeless”. Rather for most, it’s a lifestyle choice for people who love to travel and have the ability to work from where ever they are (or are perhaps retired).
I’m not going to say there aren’t any people in the situation you mention - maybe there are some - but I would think they are few and far between. If you read the reviews of any sitter who applies, you should be able to get a feel for their reliability, responsibility, and general caring for your home and pets, regardless of whether they have a permanent residence and travel part time, or whether they are a digital nomad who spends most of their year travelling.