"Strategy-proof" is a really strange thing to strive for. Making dishonest strategic voting "really really hard" is more than good enough.

By way of example, exploiting a strategic voting vulnerability in certain ranked ballot elections can require both near-perfect information about how everyone else is voting and then solving an NP-hard math problem.

Saying that such an exploit is theoretically possible and then to start talking about dictatorships as being immune is like saying there's a risk someone will win the lottery unless we ban earning money.