I thought we were all told a few years ago that it wasn't possible to rig an election, at least not to any degree that would change the outcome. A lot of people were called crazy or worse for believing it might be possible.

Conflict of interests. We were told these things by the very same people who have an interest to rigging an election :-)

at some point, this problem boils down to something like trusting trust and I think that the answer might be similar to how stage0 in compilers work in that smaller stages which can be easily audited combine/compile together to form larger stages. (Not sure if this allegory fits at the moment but I do feel like decentralization can definitely help in these cases which is my point but these same people who told that it wasn't possible aren't looking for/actively hindering any prospects of decentralization due to once again, conflict of interests)