WORLD OLDEST SITTING PRESIDENT OF NATIONs, why are world leaders in their late eighties leading nations in this 21 century, can analog lead digital?

 WORLD OLDEST SITTING PRESIDENT OF NATIONs, why are world leaders in their late eighties leading nations in this 21 century, can analog lead digital? I strongly believe this is wrong, at a certain age a leader become an adviser using his wealth of knowledge and experience to advice not to lead this is the major cause of current world issues, things changes, so life changes also age and leadership are very important factors

look at this data---

1 Paul Biya President of Cameroon1982 13 February 1933 89 years

2 Mahmoud Abbas President of the Palestinian National Authority, President of the State of Palestine 2005 15 November 1935 87 years,

3 Salman bin Abdulaziz Al Saudi King of Saudi Arabia 2015 31 December 1935 87 years

4 Francis Pope of the Holy See, Sovereign of the Vatican City State 2013 17 December 1936 86 years,

5 Harald V King of Norway 1991 21 February 1937 85 years,

6 Cornelius A. Smith Governor-General of the Bahamas 2019 7 April 1937 85 years

7 Nawaf Al-Ahmad Al-Jaber Al-Sabah Emir of Kuwait 2020 25 June 1937 85 years,

8 Ali Khamenei Supreme Leader of Iran 1989 19 April 1939 83 years,

9 Margrethe II Queen of Denmark 1972 16 April 1940 82 years

10 Michael D. Higgins President of Ireland 20 11 18 April 1941 81 years

WORLD OLDEST SITTING PRESIDENT OF NATIONs, why are world leaders in their late eighties leading nations in this 21 century, can analog lead digital? I strongly believe this is wrong, at a certain age a leader become an adviser using his wealth of knowledge and experience to advice not to lead this is the major cause of current world issues, things changes, so life changes also age and leadership are very important factors