You haven't dispelled this at all.
You literally can't reduce revenue on paper when your business revenue is credit card payments. The payments get reported directly to the IRS by the card processor. You can so much more easily fudge numbers if you take in primarily cash.
In both cash and credit scenarios the business owner can increase on-paper expenses to lower tax burden, but there's only so much you can do with that without doing things like spending money on unnecessary costs or risking obvious audit discrepancies.
If you take cash you can just lie and know that if you ever get audited there is no paper trail apart from the one you have created for yourself.
The guy running the cash bar down the street can buy half his liquor from Costco with cash that he never reports receiving, and just pretends like half the bar's sales don't exist. That person would then only report the revenue to the portion of drink sales that go to a legitimate distributor.
In this scenario both the distributor and the bar's receipts all line up and look legit, so the IRS would literally have to come down to the bar and count customers to prove anything was amiss.
We can call this "financial mass surveillance" to make it sound bad and scary, but what's more scary to me as an average taxpayer is businesses evading taxes so that all the things I depend on like Medicare and Social Security get underfunded. As a W2 individual, I have no way to avoid taxes in a similar way.