Why not just have one payment system to rule them all run by the government that is required by law for all payment of employee-driven services? Businesses could save a TON of money on payroll systems and HR.

A government-run system--presumably--would take care of withholding the correct amount of taxes and also making sure the business/person paying a salary never has to worry about running afoul of the law (having the IRS or equivalent) come after them.

In France there are more than a hundred mandatory numbers on the paysheet. Each class of worker has its own retirement/health/subhealth/old-age-health/unemployment/family benefits. Each has a different rate.

The problem is that the revenue leakage for babysitters and other under the table services is lower than the scaled grifts that an “easy box” would generate.