So many posts, so much evidence that the hard of thinking are online today ....
A discussion about taxing wealth is about the method and basis for a tax ... not a commitment to tax at any particular level. I really cannot fathom why so many people are making assumptions about the level of tax that may be levied under either approach.
It the rate of a wealth tax were set at 0.001% of wealth, a person with a million in cash in a bank account would pay a tenner. If it were set at 45%, (like higher rate income tax), they'd pay £450k. That's quite a spread. Clearly it would be stupid to use the same levels of tax for wealth as you do for income., but there ought to be some level that would be electorally acceptable.
If you pointed out that presently, people already pay income tax on interest and dividends. So the same person as above with a million in cash, earning 3% interest, has income of £30,000 per year, and if they are a higher rate tax payer they currently have to pay £13,500 in tax. That is identical to a 'wealth tax' of 1,35%.
Calling it a wealth tax or calling it an income tax doesn't change the nature of taxation. It is just a different mechanism used to calculate the amount of tax levied. There are some advantages to levying the tax based on a assessment of wealth - it is harder to avoid, for one. There are some disadvantages too - mainly psychological ones, but there are also some practical ones about hard-to-value assets and liquidity. There are some advantages to taxing income - not least, the fact that the income transaction means that there is ready cash available to pay the tax at that instant, but there are some disadvantages - not least, it is possible through clever accounting to disguise, and minimise income whilst still enjoying non-cash benefits from owning assets, and thereby to avoid tax.
Broadly, if the obstacles to taxing wealth could be overcome, you could broaden the tax base and require each individual tax payer to pay less overall, for any given level of government spending. But it seems, from the comments above, that most people prefer to pay 45% income tax on incomes above £50k and to let the super rich off free. There's really no helping some people ...