Will it be considered illegal to go to work in the United States without going to school with valid visas F 1 and I20?

Yes, even though I know that some intermediaries in China use such illegal means.

It's illegal and it's not good for you.

Because the f 1 visa will invalidate your f 1 and i-20 if you don't report to school to continue your studies, and you will stay in the United States illegally from now on.

Secondly, the legal work of f 1 visa is within 20 hours per week, especially during school. I-20 can be revoked if it is illegal to stay off campus or overtime.

Then you take f 1 to apply for a job in the society, and a real American employer will not hire you. No, it won't. So I have to work secretly. In some places, your income is low and you are exploited. You should be on tenterhooks.

Don't do this.