> That worth has been reduced by the cash paid for the retired shares.

It doesn't work this way. Companies aren't valued based on how much cash they have on hand. They are valued based on the future value of their returns which should be several orders of magnitude more than whatever cash they are spending on buybacks.

Apple has spent over $500b on buybacks over the past 10 years. By your logic, they should be smaller than they were when they started. A healthy company spending money on a buyback doesn't affect their ability to earn money in the future which is the basis for the companies valuation.

Likewise, dividends don't devalue a company. A company is valued based on their future earning capacity, not based on how much cash they have on hand.