I don't understand the reason for electronic voting. The UK manages to tally up paper votes overnight, even from far-flung Scottish islands. Electronic voting is literally solving a problem that nobody has.
So more populated countries have more potential poll workers to choose from. Isn't this a linear relationship? What does size have to do with anything?
UK population density (people/sq km) is 289 and Switzerland's is 228, so not very different. Plus Switzerland is fully connected, there are no remote islands.