Why do some states wait until an election to count mail in ballots?
1. It makes no sense to wait until an election to count mail and ballots because this increases the likelihood of someone not getting caught for voting twice once by mail and wants in person.
2. It makes the US look bad if it took us several days to complete an election that could have been prevented if we counted over a million votes we received several weeks ahead of the election instead of waiting for the day of the election
With regards to depressing votes the way the electoral college works it's designed to depress the vote. The electoral colleges designed to have a winner take all and unless someone vote made a difference in a contested race their vote was counted but it didn't make a difference