As someone who actually worked with the DNC a decadish ago, the issue is the organization has been hemorrhaging talent for a decade, and hiring pipeline became horrid in the run-up of the 2020 primaries, because it became multiple internal turf wars, as state level Dems were stagnating in states like CA and IL, thus leading to dissent internally.

The moderate vs progressive culture war didn't help internally either (eg. asking whether "Latinx" might be alienating Latiné voters wouldn't end well if you wanted a career in the CA and TX Dems).