I have watched President Biden's press conferences, etc., and it's obvious he is not as sharp as he was previously. He has problems reading the teleprompter, forgets what he was saying, etc. Our allies overseas have noticed - if you follow the BBC or Australia's news services, they are quite disparaging about President Biden.

That doesn't mean he has dementia, however, and I agree with you that people shouldn't say that.

However, I was surprised when Biden won in 2020 given the many great candidates that the Dems had. Even Bernie, who is close to the same age, was much more energetic and cogent in interviews, debates, etc. And there were several fantastic younger candidates.