He is unfit, even if he is in full control of his mental facilities. And those who think he is fit won't be swayed by anything the mainstream media says.
As for Biden, if the debate didn't give you a wake-up call, then nothing will. I have, unfortunately, enough personal experience that I don't need a neurologist.
But again, it isn't about awarding a position for past accomplishments. It is about choosing an electable person who is capable of leading for the next 4 years. Recognizing that that person isn't Biden isn't trashing Biden. No one is capable of being president forever. He is still a good person. He was still a good president.
But a lot of us have to take the car keys away from elderly parents or spouses when they can't recognize they are no longer safe to drive. I am not saying he was at that stage - far from it. But some firms of cognitive impairment make it impossible for the person to recognize they are impaired. My spouse has that kind of impairment. With that personal experience, Biden's failure to recognize how bad the debate performance was worried me more than the performance itself.
And again, it isn't about rewarding or trashing Biden. It is about doing what it takes for what the country needs. And sometimes that takes a wake-up call from people with a more objective view than the person impacted.