Yes, we need to draw a line at voting. It's a single event, where a choice that can be encoded in a single byte of pure information has enormous consequences in terms of power allocation.

If you can change that byte across even a small percentage of voting machines, you can leverage that into control of the country's government.

All of the examples you listed are continuously running, auditable, highly heterogeneous systems that can have multiple parties cross-checking because there isn't the absolute need for the actions of the participants to be untraceable back to them, the way it needs to be with voting.