He's 4 years older than his rival. That's not huge. He rides a bicycle daily. He rival rides a golf cart and looks like he's one big mac and a diet coke away from a heart attack. He nearly died of covid when he had it. Biden beat Trump very, very handsomely in the last election. Trump's backers have largely evaporated and he's gotten boring. The chance that Trump beats Biden in 2024 is near zero. Trump wouldn't stand any chance if the Dems stand a younger and more dynamic candidate.
Furthermore, Trump supports Putin. Game over.