If you don't understand a concept that's part of the stock market, reading the Investopedia article will go a long way. It's a nice site for basic overviews. https://www.investopedia.com/terms/b/buyback.asp
The short answer is that the trend of frequent stock buybacks as discussed here is not being used to "eliminate debt" (restore private ownership), it's being used to puff up the stock price as a non-taxable alternative to dividend payouts (simply increasing the stock price by reducing supply does not realize any gains, while paying stockholders "interest" directly is subject to income tax). This games the metric of "stock price", which is used as a proxy for all sorts of things including executive performance and compensation.
The short answer is that the trend of frequent stock buybacks as discussed here is not being used to "eliminate debt" (restore private ownership), it's being used to puff up the stock price as a non-taxable alternative to dividend payouts (simply increasing the stock price by reducing supply does not realize any gains, while paying stockholders "interest" directly is subject to income tax). This games the metric of "stock price", which is used as a proxy for all sorts of things including executive performance and compensation.