“....according to delivery drivers who either witnessed the arrests...”
In the big cities (like San Francisco) large groups of all Mexican/Central American men with an occasional woman congregate in high demand areas on their electric bikes, holding several phones, waiting to deliver for Door Dash, Uber Eats, etc.
It is well known that most if not all are illegals working under false accounts which are up for sale on various sites. That or they are working to pay off smugglers with fake ids and they are making very little money.
Americans who used to do this work to pick up some extra cash or have a low commitment pick up job are priced out. These guys might make $5/hr.