Earlier quoted context omitted.
Parent could be talking about the scanning and tabulation. In theory, there shouldn’t be anything problematic with “you vote on paper, and then slide it through a scanner, from whence it goes into a sealed bin”. Then you can still hand-recount.
In my country (UK) the results are known pretty much for certain the second the polls close. The results for certain are known within a few hours. We use paper and hand counting. Why do you want to use scanning? What problems do you think it solves that we haven't solved with paper and hand counting?
There are many races to vote in at the national, state, and local level. Besides President, every ballot would have included house rep and 2/3 of states had a Senate race. Then add state governor, house rep, and senate which often align on the same cycle. Most states also elect attorney general, treasurer, education and several other statewide executive offices. Some states elect state supreme court judges. Then there can be mayor, city council, school board, port commissioner, and other local offices, although many states align these to non presidential election years. Then there are states like California that always have several initiatives.
In practice, you are looking at dozens of races on this year's general election ballot in many states. Counting all those on paper would be time consuming and possibly less accurate than using an optical scan counter.