In some ways it is and in some its not. Personally I do believe that there shouldnt be an exemption to minimum wage laws for farm work, and that is messed up.

That said, it still wouldnt change the fact that those would be the primary jobs taken by migrants. The baseline for most entry level service jobs in the US, which makes up the majority of jobs available, is that someone has a highschool level education and is fluent in speaking English. Even that is just a baseline for making minimum wage or above it to whatever degree the market ends up setting as the functional minimum. Even if they did speak English more fluently and had a GED, then there is still a ton of competition in that market segment because those are generally the basic standards required to be met by every native born citizen at the very least

Migrants arent getting underpaid just because people dont want to pay them. They are getting underpaid because they dont have that many options to not be underpaid in the way the economy functions right now. Its also part of why they take the risk of starting businesses more often, because then it really doesnt matter if they meet minimum standards of communication or education.

And as much as it is in many ways exploitative, the same would be true in the inverse. You could have a PhD in the US but realistically not be able to do much other than drive an uber if you moved to Medellin or Mexico City or whatever. Youd need to be fluent in Spanish to get anything other than a low paying job. Its market forces more than anything