'a lot of them' means exactly nothing. How many? Do you have some numbers?
Last time I checked, the dept of labor was saying that about 40% of all agricultural workers are illegal immigrants and United Fresh Produce Association between 50 and 70 percent. So yeah, a lot of them don't use 'legit' systems. It must be very hard to cheer for building 'the wall' while employing illegals and getting federal subsidies. That's why I have great faith in farming automation as it would provide some well deserved relief.