The Russia conspiracy theory hinges on the single creaky claim that the Democratic National Committee hacks were a Russian plot to elect Trump. The theory and all its illegitimate stepchildren, including Robert Mueller and his infinitely expanding corps of prosecutors, lives or dies by the DNC hacks.
Trying to elect Trump by releasing damaging insider information from the DNC never made any sense. The DNC was already a dysfunctional organization that was being run by the Clinton campaign. Undermining its leadership had little impact on the election, but a great deal on control of the DNC.