You can keep saying the sky is brown, but I'll keep seeing blue. You can link a study proving conclusively that Joe has the mental acuity of a thirty year old, and he still won't be able to utter two coherent sentences in a row.
There is no "convincing" involved. The man is suffering the mental decay of old age, a fate that awaits most of us.
Do you think Pence will be president within two years if Trump wins? If not, you might want to reconsider how biased your thought process is. If you do though, I think you're similarly delusional when it comes to Trump. I get that you hear from right wing media a lot that Biden is somehow mentally infirm. This is because they have decided on this line of attack because they don't have anything else. You're getting duped yet again.
The good news for you though is if you genuinely think you're the one who sees things clearly I am very confident that you will be able to make a large sum of money betting on this outcome. Like, a LOT of money. Something tells me you will not avail yourself of this amazing opportunity.