I'm genuinely not sure what you're trying to say. Obviously processing mail-in ballots won't take long if there aren't many. But as I've shown, countries with uncontested elections have many people voting by mail, so unless you're contesting the German elections this by itself isn't suspicious. And since states have rules about when counting is allowed to start, it's also obvious that counting them will finish later.
My point is that other developed countries are perfectly able to have a transparent electoral process and present the results in very little time, even doing everything by paper voting.
Arguments that you need voting machines, or extensive mail voting, or pre voting, or not check a valid photo ID to be able to carry out the process in due time, are completely against what the reality shows in all other developed countries.
And yet other developed countries are perfectly able to have a transparent electoral process and present the results in very little time, even doing both paper voting and mail-in voting. Why deprive your citizens of mail-in voting when it's not necessary for safe elections? If you remove the laws that make mail-in voting take longer to count, it will not take as long to count.
Additionally, you seem to be willfully ignoring the differences regarding photo ID between the US and most other developed countries. Why?
Are you trying to say that the process doesn't work fine in Germany?