I didn't see all the speech or press conference, but I've seen multiple clips including a 5 minute clip from the speech. Biden certainly talks like an older person and you can tell he has dentures but...he looks like a pretty normal politician. When you spend months telling people that he is mentally gone, he doesn't know his own name, he can't do xyz...and then he goes out and is normal...you blow up your entire argument. This reminds me of the attacks on Obama being some radical black racist who wanted to destroy America...then the average person would see him and be like "he's just a regular guy."
Biden is calm and competent. All that matters.