There are other concerns of course---
-- Would tax planning then become a race to spend all your money on things that would not be considered wealth ??
-- How do you police it?? I tell the tax authorities that I spent all my money last year on wine women and song while I meanwhile have gold bars, jewels etc in a safety deposit box--
-- People like farmers can have a lot of "wealth" in the value of their land but without selling the land, they would have a problem paying more significant levies. In fact, any lower-income people that happened to own a home in an appreciating market could have a tough time paying their taxes
Its an interesting idea . . . I have no problem with trying to get something from the super rich BUT I don't see it as a feasible replacement for income tax