I remember the VP Biden-Ryan debate in 2012. Everyone thought Ryan would eat Joe alive, especially on budget issues. Ryan was a data guy. Joe demolished him essentially by lying and making things up. Fact checking after the debate was futile. Most viewers don’t hear the corrections. The damage is done.
Joe is an inveterate liar. He lies about everything. Even when confronted with the truth, Biden will say that it isn’t true. Joe would make mincemeat out of DeSantis. It took the first debate for Trump to figure Biden out. He was beating the crap out Biden in the 2nd debate until the moderator intervened on behalf of Biden.
That's why Joe's handlers will not permit him to debate Trump (if he wins the Republican Party nomination) the next time. Trump will probably insist on a moderator (someone who he knows) who's fair. But Biden will never agree to that deal.