Given that the system is heavily skewed toward incumbency, your comment is a bit disingenuous. We both know that the DNC intended Biden to run. He had the advantage of thier coffers, thier PR machine, and the support of their leadership. Implying that the playing field was at all fair ignores reality.
I do agree, though, that Biden's many faults are his own. His most recent failure, support for ethnic cleansing and denial of aid to refugees, should have made him unelectable by the party that claims to be pro-human rights... but here we are, with him as the best of two terrible candidates.