The votes can be tallied instantaneously through the electronic system, but if there's any irregularities the lockboxes can be opened and manually counted as verification. And you can open a small number of randomly selected lockboxes every election anyway, even absent any suspected wrongdoing, just as a check to verify that the electronic counts are working as expected.
How is this not the standard everywhere? Yes, there's more paper (and thus expense) involved, but surely having a non-hackable paper trail is worth it to protect our democracy?
I was at DEF CON the first time they did the voting machine hacking. Those did not fill me with confidence.