Honestly? You'd have to show me the spreadsheets to prove that assertion. Not that the current system in any country is likely to be 100% efficient, mind you, but I suspect it's more efficient than you give it credit for. That said, that's hand-waving in both directions. I have no numbers to support my own suspicions, either.

Also keep in mind that it isn't half of everything. These systems are typically progressive, so it's likely because this will be a large sum ($220,000) all at once that the tax rate is that high.