That article doesn't go into enough detail to be able to even be able to refute their proposals properly!
So I'll just refute the usual conspiracy theory crap people come up with on the subject.
Yes, capital gains % is lower than income tax. It's set that way to deal fairly with inflation and capital losses. Sure some countries calculate capital gains tax taking those into account, but it's much more complicated (which means more expensive to collect) and comes out about the same.
Wealth tax generally loses more than it makes, since the people you want to catch in it are generally mobile. France tried it, then reversed the law a few years later, having calculated that they had lost billions directly due to the tax as well as reduced their GDP growth.
There's a common argument that people on lower income pay a higher percentage of their income in VAT than richer people, often used to claim that VAT is regressive. That's actually incorrect: it only looks that way because people's income fluctuates more than their outgoings. When you're temporarily down on your luck, you spend your savings, so the amount you buy(and so the VAT you pay) is a higher proportion of your current income than usual. When you earn more, you put more in savings, so what you buy (and your VAT) are lower than usual. You'll still pay the VAT - but only when you spend your savings! Actually, higher income people pay more VAT than lower income as a proportion of what they spend... exactly as you would expect, given that so many necessities are exempt from VAT. (To be fair, your article doesn't make this mistake).
It's a ridiculous myth that rich people don't pay their share of tax. As a pp said, they pay a huge - disproportionately high - amount of tax. Both in absolute terms and as a percentage of their income.
This disdain for wealth, business etc are exactly what leads to the breakdown of the social contract @arttheclown talks about. And to the enshittification of our society she mentions too