The person you're responding to was suggesting a wealth tax though, not an income tax. With a wealth tax you'd pay some percentage of your wealth every year, including on your properties. It's not a crazy idea; either. France, along with many others, currently have a wealth tax: https://en.wikipedia.org/wiki/Solidarity_tax_on_wealth
They were hedging their recommendation, saying that we could have a wealth tax but maybe it isn't necessary because your gains on capital are all taxed anyway. The wealth tax obviously suffers from massive tax evasion as well.
Yeah, I'm not in favor of a wealth tax, precisely because of the evasion problems (which France is experiencing). I think a better and simpler solution is to not have abnormally low capital gains rates. And did you know that someone who is wealthy, who owns stock worth millions of dollars, pays $0 federal income tax until they reach over ~$80K in qualified dividend income per year? It's absurd. Income should be taxed the same regardless of source. Maybe give a slight tax break of ~5% for long-term investing of, say, 5-10 years or more, but getting a ~20% tax break for investments only a year old is absurd.
Of course, the most effective wealth tax of all time was implemented centuries ago and is continuing to perform amazingly. I'm speaking of the elimination of primogeniture, which does an excellent job of breaking up multigenerational wealth (and thus largely prohibiting the establishment of a permanent nobility class).
In Canada they have 'tax free savings Accounts'. It basically is a small allowance to invest tax free. You can add 5k every year. It actually allows compounding, so some people have managed to create 'large' accounts totaling more than hundred thousand dollars, although they could've at most contributed like 50k. The tax authority is trying to crack down on people trading in this.
Other than that, all dividend and interest income is taxed as normal income, all capital gains are taxed half income. Si those 80K of income would put you in a high tax bracket.
Fair. But most investments will incur some taxes when you turn them into something liquid like money. You know, if you actually want to benefit from the wealth that it represents.
The personal home is one of the few exceptions (at least in Canada, where there's a 'principal residence tax exemption'). But even there you need to pay at least some property taxes. Can you think of others?
On the other hand, that person will generate interest income, which is taxed normally anyway, at a much higher rate overall.