[pc86]

Because you don't certify the vote of the USA. You certify votes in precincts that get a couple hundred, maybe a couple thousand votes. Then you aggregate up and up to each state and start assigning electoral votes. I was a poll watcher for many years, for both the state party and individual candidates. Our polls closed at 8PM local and by 8:10 we had certified counts sent to the county office, unofficial results taped to the door and we were headed home.

There is honestly very little reason to have election counting take days unless there are irregularities and the vote tally is very close.

[specialist]

Poll sites, yes. Though adding provisional ballots, which are adjudicated later, did create a spike in problems.

Central count for postal ballots, however, absolutely will take days. Please see my other comment.

Many jurisdictions have automatic recounts at certain thresholds. Another delay.

And IIRC there's 3m overseas voters. Those ballots trickle in.

Also IIRC, most jurisdictions certify their elections 3 weeks after the election day.

Given all that:

Most candidates will concede prior to certification when defeat is obvious.

And corporate media will do whatever to boost ratings.

And everyone will whine about bias, coverage, not getting enough ice cream.