That is the beauty of a democracy. Leaders come and go. It is normal procedure. Even in kenya, uhuru left. Nothing special. The likes of your idols Putin, Idi Amin and Xi Jinping overstay their time. Of course Biden will go. Earliest 2024. Nothing new in the US.
Btw, what do you mean consumed the heads of these countries?
Same way you thought Aug 2022 is far . Leave alone waking you up , you will have Rude Awakening.
As for who it has consumed just off my head 2 Britain P.M. , Italian P.M. Swedish P.M.
To mention but a few.