> nor do they make grossly overvalued shares more reasonable
Yes they do, as a share buyback improves every valuation metric on a per share basis.
Buybacks are a logical way to distribute profits back to shareholders so the attack on them was always a bit off. The biggest knock on them was probably that companies had lots of debt which made these not worth the risk - but given the interest rates and inflation all debts have been easier than ever to pay back.
On the other hand, if you're a day trader, that company is as good for gambling on as any other.