- buybacks are taxed when a person gets money for their shares, as capital gains tax

- lots of corporate tax is about exactly the opposite of what you say; i.e. reaching inside a company's bank account and taxing its profits directly, rather than waiting for the money to flow out and taxing it as VAT/income tax/cap gains. A huge amount of money and effort is spent on balancing this correctly, with R&D credits, structuring profits to appear in the correct year, etc etc.