He converted his stocks to Treasury bills and spent the interest to live, on which he continues to pay taxes. Eventually our friend dies. His heirs will wish he had. Everybody pays multiple taxes on their incomes. Coming on top of all the other taxes, the effect is to significantly reduce the stock of capital, which is the ultimate source of jobs and wages for all workers.
Estate taxes are especially costly to family-run businesses.
In order to keep their businesses in their families, those who founded and nourished them to a modest size must expend vast resources to do so. Not only must they engage costly lawyers and accountants to devise complex estate plans, but they must often pay large sums out of current revenues for insurance policies that are needed primarily to pay the estate tax. Failure to buy such policies often means that family businesses must be sold at a fraction of their value to raise cash to pay estate taxes. The white millionaires care nothing about the problems of struggling family businesses. Most of them inherited their wealth in the first place, and those that didn't are known to have made extensive plans, all perfectly legal, for preserving their wealth from the tax collector.