That should be common sense to anyone literate or numerate. The number of votes scales up with population. The ability to count votes also scales up with population. It's basically linear, or actually better because they break up large areas into smaller districts, and then they have people counting in parallel. There's absolutely no reason the counting should take longer than expected. Even in the Clown World election of 2020 where they didn't require people to register (lol), they knew how many ballots were sent out. That would give them an upper limit on the returns. The only way to screw up was through fraud or extreme incompetence which gives us the same result.

This is why I consider anyone who thinks the election was basically fair and accurately reported to be corrupt and a willing participant in the steal.