I'm a white American who grew up harvesting tobacco on the side. It's not a gig Americans are willing to do. It sucks, it's dangerous, it doesn't pay all that well, and it's seasonal. For reference, I quit cutting tobacco in favor of cleaning out sand filters for sewage treatment plants. Which is to say, shoveling literal shit out of a hole in the ground is preferable to being a farmhand.

The American people you see doing this stuff are by-and-large the family of the land owner or teenagers whose backs are still functional (and have school duties during the off-season).

If you have a family, then you're going to need either a primary job, or an RV to move around. The only people making money farming are the land owners, and even then...