The point is not open source code. You still have to place trust in the system and the people executing it. While this is also true for a paper based manual-counted system the later is so transparent to anyone that cheating becomes very very difficult.

Source code will never be transparent to anyone but programmers.

I admittedly don't know much about crypto voting. What I do know is this:

When the entire process is analog I (and everyone else) can transparently verify what is going on. From I submit my vote to it is counted so many people are involved from all political parties that cheating becomes virtually impossible.

Once you start to digitize the process you loose transparency completely. I can not see what is going on. The counting is computerized. I have to place trust in however implemented the algorithm. Also since I don't know much about crypto I even have to place trust in the guy telling me he did it right.

I loose my ability to verify that the process is running untampered...and I'm a clever guy. I know CS and math and what not. Imagine the alienation of common people without IT education

Voting is just one of those things that should not be computerized - there is no benefit. The current model is even costless since the people involved in the administration of votes and counting are volunteers (at least in DK).

They are designated by the party, not just people who walked in and declared they will be observing the voting process on behalf of the party.

And the non-party people are chosen at random from inhabitants of the area, they pay you a misery and most of them don't want to be there, they just want to finish and if no one says nothing and everything is correct they go home if not maybe they have to begin again to count so they are motivated to do it right.