First and foremost, there will be no defending Joe Biden on this site. My position is that he cheated in the 2020 election and Trump crushed him.
With that said, I also want to be honest about what Joe Biden said and what he may or may not have been saying.
He said, referring to the “defund the police” movement, “that is how they beat the hell out of us across the country”. (https://twitter.com/i/status/1337308649337851908) The recording stops there so we don’t get any more context than that. But to say that he was admitting that he rightfully lost the election is to interpret the ambiguity in your own favor.
He might have been saying that they used that claim in the campaign to “beat the hell out of” them while campaigning. If he had said “that’s why we lost the election” then I’d say that we have something here. Unfortunately, I think this argument should be discarded from the mountain of other valid evidence that verifies Biden lost.