By "millennia" you mean "at most 300 years, maybe"?
For the record: I don't think that priests should be able to buy $50M jets or keep 40% of total land of x country tax free, but they should not be forced to sell buildings because property tax is too high.
Churches are routinely handed over to the state or to commercial entities in order to preserve them because church membership is in rapid decline and its very expensive to take care of the church building especially if it has "survived millennia".
It absolutely has not survived millennia. What you call your Christian church today would be unrecognisable to the faithful of a century ago, never mind two, or five, or ten, or twenty. Or are you acknowledging that Christianity is the cult of Mithras, and that it’s still a death cult?
It has severe financial issues at the moment - maintaining the courtyard alone costs £1k a month. I’m waiting for more detailed finances on that.
Maintaining finances for any organisation is a basic bread and butter protection against corruption. I don’t see what harm there is in taxing religious organisations the same way as any other charity.