It's really a joy arguing with you guys, it's so rare to meet people who are capable of holding two contradictory ideas in their heads simultaneously. Biden himself has explained in the interview you provided that he's managed to find a way to avoid stuttering by changing his cadence. That doesn't mean he magically got cured, but it does mean that his ability to speak has improved dramatically, which was observable throughout his career.
There are so many "bad faith" arguments on the Democrat side that are at odds with reality one is spoiled for choice when it comes to discussions like this. Trump now has "neurological damage", he's also a mastermind behind an international scheme aimed at changing the results of an election - simultaneously a vegetable and a genius. He's a horrible businessman with a proven track record of failure and bankruptcy, he's also somehow making millions via some undisclosed means - he's bad with money, but he's also good with money. He's not charitable at all, besides that time when he gave the entirety of his presidential paycheck to charitable causes - he doesn't donate any of his money, except for the times when he does. Biden is not in the state of mental decline because he knows how to ride a bicycle, an achievement you'd praise a child for, not a grown man that consistently makes up stories that his audience needs to unravel into multiple separate stories before they make sense - he's fit as a fiddle, except the fiddle is out of tune. Trump is a bad president because he golfs 5 days a week, that also makes him physically unfit somehow - he's a fat sportsman.
It's hard to treat conversations like this seriously, it really is. So now, after all is said and done, I'm not allowed to have an opinion because "I'm a moderator". Alright, have it your way, I've said my peace already. Biden invented a coping strategy for his stuttering problem, a strategy which now fails him at an alarming rate, which wasn't the case in the past. That is, by definition, mental regression. He gained, and lost, an ability. I don't need a "cursory google search" to confirm that, I have eyes and ears. You're more than welcome to have a different opinion, but while we're on the subject of coping mechanisms, I think you should have a long look in the mirror before you point that accusatory finger at me - I see a lot of coping going on, and it's not coming from my camp.