Most people in prison are not professional criminals or part of "the criminal class". They're ordinary folks like you and me who have done something wrong, usually in a moment of weakness or stupidity, or who are being punished for a victimless crime.

Completely wrong. You clearly don't know people who have been to prison.

There are a handful of innocent people in prison, like the Jan 6 protesters. While I think weed should be legal, you aren't innocent if you go to jail for selling it. And the people selling it have already decided that the criminal life is for them and the break any law they think they can get away with.

The existence of the "criminal class" is a one of those lies we as a society tell ourselves to justify our failures

It is what I have seen growing up poor in a big city.

The main difference is that upperclass criminals have people to do their dirty work for them.

That is nothing but propaganda. The criminals in the upper class are the exception. There is a very very different perception of integrity, morality, honesty, loyalty, and personal responsibility between the classes of people. It is not a hard rule but the spectrum is shifted just like IQ.