A country that says it values work should look carefully at the way it taxes a wage compared with the way it taxes the ownership of assets. I think the difference deserves more attention than the usual argument about whether the rich should pay more.
That doesn't mean capital income is untaxed. A company's profits can face corporation tax before a shareholder pays tax on dividends. Assets may have been bought with income that was already taxed. Those points matter when comparing headline rates.
Capital can also move, and badly designed taxes can discourage investment or raise much less than promised. An annual wealth tax isn't an automatic answer to every unfairness in the system.
When the tax becomes due
A wage is generally taxed as it is earned. The employee has limited control over when that happens. An owner may have more scope to decide when to realise a capital gain, and therefore when a tax liability arises.
There are important exceptions and qualifications. Dividends aren't taxed in the same way as unrealised gains. Pensions, homes and other assets have different rules. Inheritance can create liabilities of its own. Saying that all wealth is barely taxed would obscure those differences.
The underlying concern remains: someone living from work and someone able to fund their life through accumulated assets can face very different opportunities to defer or reduce tax. That affects the relative reward for earning and owning.
A question for the right as well
This shouldn't be an exclusively left-wing concern. If you believe in earning your way, social mobility and the dignity of work, it matters whether the tax system makes it harder to build a life from wages than to maintain one from inherited assets.
Recognising that problem doesn't settle which tax should change. The effect on investment, saving, pensions and people with valuable but illiquid assets all needs considering. A remedy can be worse than the distortion it is meant to fix.
But objections to a particular wealth tax don't establish that the existing treatment of labour and capital is fair or efficient. We should be able to examine that treatment without pretending the only choices are the present system or an indiscriminate tax on wealth.