Trump isn’t 80 jackarse. What a desperate loser this guy is. Opens his mouth and each time he polls lower.
He's talking about Biden who is in his 80s...and then backhandedly about Trump at the same time, who would indeed be 80 as President if elected to another term. So "Trump isn't 80" doesn't really refute what he said...as far as the numbers, anyway.
But you are correct otherwise - the age in of itself isn't the problem. QEII was sharp as ever at 96 - far more than many people 20+ years younger than she was...certainly Biden.