from an outside perspective
Biden is an old man who's lost touch with reality
Trump is an old man who never was in touch with reality
Biden pros/cons
While Biden doesn't know what day it is, I'm pretty sure others are running the country for him, less exposure to the public in press conferences, but probably safer for the world.
Trump pros/cons
more exposure to the public, fucking hilarious press conferences, really his covid press conferences were comedy gold, however he tends to make risky decisions, so overall world safety will decrease