Meanwhile Brazil does full e-vote for almost 30 years collecting more than 100 million votes (that's 11 times the whole of Switzerland's population). You'll get there Switzerland, it can be done. It is safer and faster.
And they probably started with small-scale pilots, too.
That said, Brazilian elections are completely unverifiable. They don't seem to be false, but it's hard to say anything that would be different if they were.
When it started, at the 90s, the machines were at least simpler and possible to verify up to the firmwares. Nowadays, they are not.