The suggested wealth tax is a tax on assets (land, property, stocks etc.), NOT on income. Working people are already taxed up to their eyeballs on their income. A high earner doctor or TV presenter pays almost half of their salary in tax and NI contributions. While the super rich typically earn little income; instead they borrow against their assets, being able to have a lavish lifestyle while paying minimal income tax.
The wealth tax suggested in the video is 2% on assets over £10 million. According to estimates, 99% of the UK population owns less than £3 million, the median being a couple of hundred thousand (including their home and depending on age, region etc.) A wealth tax like this would apply to about 0.1% of the population.
I think it's a no-brainer that we have to start closing the loopholes and make the super wealthy pay their fair share. The only question is how it can be done.