Stock buybacks come from profits which are taxed, and those who sell the shares back to the company also have to pay capital gains tax. And S corp income is tax

Stock buybacks come from profits which are taxed, and those who sell the shares back to the company also have to pay capital gains tax. And S corp income is taxed at personal income rates, not capital gains rates (except for some ridiculous 20% rebates in some situations in the new tax law (but is still higher than capital gains)).