As for wealth taxes, that on real estate is not shifted because the supply of land is classically inelastic. The tax burdens owners by appropriating for the government some of the economic rent from land ownership. In the case of estate taxes, the supply and demand curves for death are also highly inelastic, so such taxes presumably reduce the long-term return on capital in the hands of rich people. Each type of tax has certain advantages and each causes unique problems in implementation. The income tax is linked to ability to pay better than any of the other taxes.
Tax is based on available resources.
Proponents talk of the diminishing marginal utility of wealth and the undesirability of huge inequalities in a democratic society. Of the other taxes, only that on estates is progressive. The attempt to make sales taxes progressive through exemptions causes major complications and shrinks the revenue base, and doing it through rebates necessitates income tax - like calculations. In practice, however, many flows of value, or opportunities for consumption and savings, escape income tax. The realization criterion means that changes in value without transactions aren't income, even though they may fund consumption.