I completely and disagree with that. I think it's wrong on every level.
First, taxes on wealth are extremely poor at actually collecting tax. It's quite difficult to not work, or to not buy anything, so taxes on employment and on spending are very efficient with extremely high collection rates. Unlike taxes on wealth.
The latter cause people to change their behaviour, because guess what, no-one like paying high rates of tax. So if you have a million in an investment account and were planning on liquidating some of it, then if the capital gains tax is too high, you don't bother. You sit on your money waiting for the day when the rate might be lower or the allowances higher, so often less tax is actually collected than before the rate went up.
And taxing people on all their assets is extremely expensive and difficult to calculate. What is YOUR net worth? I have no idea what mine is. How on earth is the HMRC supposed to work that out? They'd need years and an army of people and it would be open to huge amounts of tax evasion with people with vast undeclared assets.
So, no, wealth taxes don't work. But then there's my second point. They are grossly unfair. People go about their daily lives and they earn money and unless they are criminals, they pay their taxes in full compliance with the law. Some of them get rich by their efforts and have wealth that they have accumulated fair and square. What right do you have to say "look at that bloke, he's rich, let's have some of his money off him". It's completely immoral. Legalised theft.
So it's wrong pragmatically and wrong morally. It's just a really bad idea.