So your answer is to work on farms for $5 an hour with no benefits, no worker protections?
Is that satire?
You do realize that Americans will 'do those jobs' once wages and working conditions rise to the acceptable, but they will never be so long as mass illegal immigration is kept in place?
Illegal immigration is a very corrosive trap: once one farmer, in economic trouble hires illegals and cuts his costs, all of the others have to follow suite - it's a thin margin game. And then it's a trap the industry cannot get out of.
Most farmers would happily employ Americans for higher wages and better conditions if economics allowed for it. But so long as there are tons of illegals, and 5% of farmers who will take advantage of it - the rest have to follow suit.
Open border / illegal immigration is a very corrosive thing.
Also - the Asians that come to America are not 'mobile'. They don't go to Alabama and Georgia, generally. They go to areas where there are many other Asian people, which is rational on their part. I don't think it's fair to compare people who have lived in some area for 5 generations to newcomers.
Jobs for the less skilled are not plentiful in America. There is a lot of opportunity for the upper 50%, but it's not the same for others.
Also - the greatest wave of automation happened long ago, in the industrial revolution. We managed to find jobs for people then, we will now.
They can migrate to the American southwest and do agricultural labor, competing with the illegal immigrants doing jobs that "Americans just won't do". They can migrate to the distant outskirts of high productivity cities (e.g. NY, SF), then commute in and provide domestic labor to high productivity individuals. There is plenty of opportunity out there; if there weren't then people from around the world wouldn't be desperately attempting to enter the US.
Hundreds of millions of Indians, Chinese and others engage in internal migration, moving themselves to where the jobs are. Americans could too.
This is just not a fix that Silicon Valley can do; if a man doesn't want to fix himself, then Peter Thiel can't build an app to do it for him.