Here in NZ when I've been to vote, there are usually a couple of party affiliates at the voting location, doing what one of the parent posts described:

> You can stay there and wait for the count at the end of the day if you want to.

And if you watch the election night news, you'll see footage of multiple people counting the votes from the ballot boxes, again with various people observing to check that nothing dodgy is going on.

Having everyone just put their ballots in a postbox seems like a good way remove public trust from the electoral system, because noone's standing around waiting for the postie to collect the mail, or looking at what happens in the mail truck, or the rest of the mail distribution process.

I'm sure I've seen reports in the US of people burning postboxes around election time. Things like this give more excuses to treat election results as illegitimate, which I believe has been an issue over there.

(Yes, we do also have advanced voting in NZ, but I think they're considered "special votes" and are counted separately .. the elections are largely determined on the day by in-person votes, with the special votes being confirmed some days later)