Earlier quoted context omitted.
That's not true. In some cantons, the very rich get extra deals, called Lump-sum tax, independently of their revenues. E.g. the Ikea founder only paid around 165000$ in total taxes in 2014 on a fortune of 46.5 billion US $ and all his revenues which he had. Source: https://www.20min.ch/story/so-wenig-steuern-zahlte-der-ikea-... )
The lump sum tax is only possible for non-citizens, who do not have direct W2 income from Switzerland. Local governments (if the state allows it) can use it as a shortcut to estimate the tax amount. Nevertheless wealthy Swiss citizen don’t leave Switzerland either. Probably also because there is no capital gains tax which offsets the wealth tax easily.
As long as capital gains are less than half of your income.