He also quite frankly appears to be on the verge of full blown dementia. And Harris is neither quite, nor nimble.
I still believe he (or Harris?) is a better choice than Trump, in the particular situation US is in because of Covid.
I've watched Biden live multiple times. He is not as skilled an orator as Obama was, and he indeed clearly has a speech impediment. None of that means dementia.
Either you fell for the old "youtube conspiracy hole", or you're seeing what you want to see.