Seriously. Go find a video of Donald Trump speaking from 20 years ago and compare it to a recent one.
The magnitude and severity of his decline is utterly horrifying. He used to be able to speak coherently in complete sentences, was able to express full thoughts, and had a vocabulary appropriate for an adult.
That is not normal aging.
ETA: Here's Trump in 1998:
https://m.youtube.com/watch?v=y4CqF4hjCGI