No the shareholders own the company so they “own” the cash either way. Buybacks and dividends return control of the cash back to shareholders so they can allocate it elsewhere.
Not exactly a 10% buy back is not 100% guaranteed the same return as a 10% dividend - and this Ignores the time value of money.
Theoretically an x billion dollar dividend results in the exact same outcome for a shareholder as an x billion dollar stock buy back. Not sure the time value of money factors in.
Dividends are not guaranteed either - companies can and do suspend dividends whenever they have cash flow or profitability problems.