I often receive a large number of 1099's in my business.
While I have not been audited, for one year, the IRS sent me a letter, explaining that they felt I had neglected to include the income from one single 1099. They were correct. There was no fine imposed, and they gave me 90 days to pay the difference in tax due, based on their calculations. It was a relatively small amount, compared to my overall income.
A few years later, when I was moving, I discovered the missing 1099 behind my desk, where it had fallen and lay in hiding for years.
Point being that the IRS unquestionably keeps track of 1099's and expects you to report the income...and will let you know if you don't, and there is money due. They don't need to "audit" you to do this. I doubt it takes more than a very small team to do this, since it's almost entirely electronically reported these days. A bill of balance due is MUCH more likely than an audit.
It's up to each person to figure their own path with reporting, but my CPA reports the entire 1099-K for me and then deducts out the reimbursements as business expenses. Yes; the amount of deductions are clearly an audit trigger, but at least it puts the ball back in their court to perform said audit.