Why did it take so long to count the other 30% of the votes if 70% was counted by November 5th?

https://pittsburgh.cbslocal.com/2020/11/05/allegheny-county-finishes-ballot-count/

https://twitter.com/kdka/status/1324343209196195842?s=21

I reported & filtered one of the CP images & I still see them on the feed. I assume multiple posters. We over the target?