Are you suggesting that there are an infinite number of jobs for farm workers?
The reason why farm workers have tiny wages and poor working conditions is that there is a massive global surplus of people who are looking for farm work.
And if you're unemployed it doesn't matter what you are unemployed at. You can declare yourself to be an unemployed auto worker, or an unemployed farm worker, or an unemployed ballerina for that matter. There is an infinite number of jobs that I'm not employed at.
You may ask, of course, why an unemployed software engineer collects more benefits than an unemployed day laborer. The answer is: Because unemployment insurance taxes are proportional to income. The engineer pays more taxes when employed, in order to collect higher benefits when unemployed.
The engineer pays more taxes when employed, in order to collect higher benefits when unemployed.
Only in theory. The reality makes far less sense.
Here in California, it's not the employee who pays the tax, but the employer, and it's only proportional to income up to $7000 per year (yes, year, not month) per employee. The payout is only proportional to earnings up to around $50k annually.