I had no issue with Harris campaigning with Cheney. Cheney and I disagree on 99% of things, but we agreed that Trump is a corrupt piece of shit. Cheney and Kinzinger sacrificed the easy Republican win to go against Trump. As did Romney to a slightly lesser extent.
To me campaigning with Cheney was a way to signal to dissatisfied Trump Republicans that an alternative exists. That your could vote for Harris and still be a capital R Republican.
I've met (e.g. was raised by) these people. I thought it was a large part of the voting population.
Clearly I was fucking wrong. Clearly this was a niche. But I understood the strategy. I see people complaining that Harris moved too far to the right but I can't think of a single right wing policy she picked up. Sure she picked up/was always following neoliberal policy, which aligns with neocon policy, but that was a given. We already had Biden, Harris was an extra step towards progressive, but not a leap. In either case I was happy enough.
Suffice to say I don't buy the argument that Cheney cost Harris any voters.