You may well be right and it will be a landslide for Biden, but I doubt it. One of the reasons it won't happen is that Blacks are unlikely to turn out for Biden in the numbers they turned out out for Obama or even for Hillary. If Trump will actually win this election, one reason will be that the Black vote for Trump will jump from 7% in 2016 to 12% in 2020. Polls show Trump has increasing appeal to Black Americans. https://www.washingtontimes.com/news/2020/aug/31/trumps-approval-rating-black-voters-soars-60-durin/
Even if you share my skepticism of polls, we also have a string of endorsements from Herschel Walker, Clarence Henderson, Ice Cube, Fifty Cent, L'il Wayne and others that could have a impact. Kanye could also siphon off 5% to 10% of the Black vote.
A wild card is the potential impact of seeing White Democrats tell Blacks how they must vote or they are not really Black. https://www.youtube.com/watch?v=pn3ZeknyaIY
Is it not racist when Chelsea Handler says she has to remind 50Cent he is Black?
Also, there is more than a bit of resentment that comes across in interviews where Black residents demand their neighborhoods be protected from rioting started by mostly White Left-wing agitators. All this could convince 5-10% of Black voters not to turn out for Biden on election day.
Finally, there are more than a few Black people at some of the Trump rallies and even a Blacks for Trump group. .https://www.publishedreporter.com/wp-content/uploads/2019/07/BlacksforTrump_lrg.jpg
Trump could win because a sufficient number of Blacks decide to escape the Democrat plantation and vote in their own self-interest.