I had a relative who was a revenue agent with a couple of highly specialized areas of expertise. When he started in the mid-80s, his unit had about 250 agents nationally. When he retired circa 2010, there was 4.
He retired earlier than he wanted because the travel was difficult and he was developing some health issues. The cases they prosecuted were people cheating society out of hundreds of millions, or in one case, billions of taxes. He characterized the scope of what wasn’t even looked at as 15k cases annually where at least $10M of taxes were notn paid. They didn’t even bother to think about anything less than $100M.
We should be vilifying the people doing this. Some of these crooks avoid taxes equivalent to 10,000 or more well paid professional like myself and my colleagues. You also have issues with some cases where the tradition of allowing Senators to nominate US Attorneys and hyper-political judges means that certain crimes are effectively not crimes in certain districts.