The most important thing is TERM LIMITS! Many of these guys have simply been reelected time and time again because they haven’t been really bad, their parties are content to just let things coast along, and most people are too lazy to ask any questions.
Don’t forget, Churchill became Prime Minister at the age of 77. And Donald Trump is now 71. So I think an age limits are far less necessary than term limits.
They are already term limited by vote every 2, 4 or 6 years...