Most of the income goes to the treasury, and the royal family is not involved in its management. There are privately held stuff that’s here and there but major items like Lancaster and Cornwall are the mechanisms for paying for the royals.
There’s tech bros with far, far more money than the royals and they don’t even do tourism. Given the sheer weight of historical documentation, the royals could probably produce a legitimate deed for this stuff. Much is rather illiquid.
Twist it however you like, end of the day the tourism stats are fantasy propaganda and it's the tax payer funding the crown. Their property belongs to the people of the UK and will one day find its way there.
The crown voluntarily entrusted the public with billions of pounds worth of revenue generating properties, from which the state keeps 75% of annual proceeds. I would say the Royal family pays excess taxes.
While Duke of Cornwall, Charles paid income tax on his annual proceeds, which seems like a double taxing
