Individual dogs are different, even within the breed, or subsets of the breed, like working lines.
We have two dogs, a male and female, close to the same age.
The female is not a low drive dog, but developed a chill switch inside the house fairly early, by somewhere between 9 months and 1 1/2 years.
The male is the younger of the two, and he constantly wants to play if we are at home, whether in or outside.
Both can be left alone, and have been, for up to 4-6 hours, without destroying things. When we are not there, they do not amuse themselves by getting into things. You do have to be smart about putting the trash out, not leaving god smelling foods on the counter, but we don't come back to evidence of a dog kegger party, so to speak.
But if the male has humans present, he doesn't really understand why they don't want to play. If you tell him knock it off, or platz! he will, but after a while he thinks its time to play again.
Out in the yard, the female really comes alive, and will play ball until your arm is tired. But she does not need constant play and interaction while in the house. More content to snuggle beside you or lie at your feet.
However, both will light up like junkyard dogs on crystal meth if someone comes up the drive. I do not believe they will ever calm down in that respect. We live on a farm, so I am OK with that. We don't have a lot of unexpected visitors drop in. The mail box is almost 1/4 mile away, so they don't really bark at the postal carrier. At some point, for me--you do you, by all means-- if I did not want a dog that had guarding tendencies and barked at strangers, I probably would not have a GSD. So I am aware of "bark collars," and I could probably correct the alarm barking out of them, but then why not just get a Basenji, or a Goldendoodle, or whatever.