2-4% of the wealth you mean? That surely depends on the wealth... If you need 200k a year that's 2% of 10 million, but 1% of 20 million.
If you manage 1% then the real value doubles after 15 years. If you need 2% annually, the real value doubles after 18 years. The moral of the story is the same, with enough wealth you can live comfortably while your wealth grows.