As I am used to monarchs who retire to make place for their successors in their prime, I have mixed feelings. That a nearly 100 years old person is still a monarch can also be interpret as: the kingship is so empty-egged that even a brontosaurus can do it.
No any of us would entrust a 95 years old as a pilot, as a CEO of or as a nurse, but being by the Grace of God Queen of the United Kingdom suddenly is no any problem at all. And that she will he succeeded by another one past retirement age: what does it say about the seriousness of this High Office? Is it all just ceremonial theatre, with gerontocrat actors?
That is why I would find it refreshing, and absolutely honourable, when a monarch indeed can freely and voluntarily lay down the kingship. As is the use in the Netherlands and Luxembourg, and has been done in Belgium, Spain, Japan and even the Holy See.
Look how Haakon, Victoria and Frederik are in their prime but possibly will succeed in their 50's or 60's.