Steve, while I agree with your overall premise, there are a few obvious errors in your examples:
1. Enterprise Rental Cars and other businesses are private enterprises. With some exceptions, they can set terms for payment. This is a government agency. Go to a public IRS office, and they are required to take payments in cash.
2. Toll roads are operated by authorities in most cases, i.e. quasi-governmental. Passengers on a railroad do not have license plates to be read. You could take a picture of a driver's license, but this would not nearly be as simple as a tag reader.
4. As someone else noted, not really applicable; a ticket for carriage on a railroad is not going to approach the $10k Bank Secrecy Act reporting threshold LOL.
5. Again, IRS gifts of cash threshold for reporting (it's about 13 or 14k before you file a gift tax return) is NA.
7. I can go to my local utility office (Georgia Power) and pay with cash. Saying utilities, etc. don't accept cash is a blanket statement that's not true.
9. Employers pay in cash all the time. I know some restaurant employees who are paid by check, and immediately cash the check AT THE RESTAURANT. Same diff.
10. "IRS requires a checking account for Social Security". They have nothing to do with each other, they are entirely separate agencies. Why would IRS require a checking account for another government agency's payments? He!!, IRS will still mail paper refund checks. That's just silly.
All due respect for you railroad knowledge, Steve! Stick to what you know!