You are right that it is not about the software. I think you are wrong thinking that it is about the protocol.

It probably should be about the data. The data should be openly available to everyone.

But there are some requirements to the data that make this tricky (understatement).

With the data in your hand it should be possible to independently verify the results. It should be possible to individually verify that your vote is somehow in there. But it should NOT be possible to link votes to individuals, it should be completely anonymous.

This is not a problem that is likely to be solved by software engineers. If there is a solution, it is in crypto and math more than software.

I do think this is an important problem to solve. It would enable the ultimate democratization. Instead of voting for representatives it would become feasible to directly vote on issues by referendum. If tech is about anything, it's about democratization and cutting out the middle man.