As the wise philosopher Benjamin Parker said, "With great power comes great responsibility." If you want the power that comes with a top-level role in the U.S. government, then you have a responsibility to give the public accurate and timely information about your health, particularly if you are elderly.
This goes for President Biden, former president Donald Trump, Senator Dianne Feinstein and now, indisputably, 81-year-old Senate Republican leader Mitch McConnell.