All lives belong to God. He decides when to grant rest and when to keep alive.

President Buhari has more years to live, whatever his shortcomings in Government, pray for his survival.
If your father is not doing well at home, you won't pronounce him dead, he is still your father, In a similar vein, President Buhari is the father to all of us Nigerians, and remember some of us have fathers at home with same grade level with Mr. President, some battling one Ailment or the other, as children let pray and wish them well, God, in turn, will grant us health and longevity to see our great-grandchildren in the future.
One day we will all grow old and inactive, how will you feel if people pronounce you dead when you still alive.

Please let stop wishing Mr. President dead, rather pray for grace to live above and beyond him.

The bible categorically states:
(Timothy 5;1) Do not rebuke an older man, but appeal to him as to a father. Treat younger men as brothers
(Leviticus 19:32) You shall rise before the gray headed and honor the aged, and you shall fear your God [with profound reverence]; I am the Lord.