> taxation of stock buybacks (which is a way to pay dividends without paying income tax on them

I don't think you've got the mechanism correct here. If a corporation has cash, they can pay dividends which lands in the pocket of every shareholder equally. Or they can buy those shares back from shareholders who are willing to cash in. If I hold shares and don't sell in the face of a buyback, I'm not getting a dividend. Instead, my on-paper wealth has increased by the amount that the buyback juiced the price of my shares. If I do sell, then I pay short term capital gains (which are effectively the same rate as income tax) or long term capital gains (which are lower but probably not low enough to offset the extra tax created by inflation)