I have not seen this myself, but I have relatives that own several rental property and they often see people in Home Depot parking lots just standing around waiting for work. They’d then talk to them and offer them to work on their properties. I think the reason is that these are likely either undocumented immigrants or new immigrants that cant find a job, so they just stand around hoping someone will offer them work. They are probably cheaper than a US citizen worker doing the same thing. Although, the quality of work will vary, and the quality of their work is… questionable. (I mean, they aren’t gonna have licenses or anything)