They try to adhere to the rules. In practice, there is a lot of variance within a single building.
For instance, my friend managed to do something by email. The same day, I got an answer from the same office confirming that it was impossible.
I spent months documenting the freelance visa application process, and worked with several relocation consultants to document it. A person I helped got a 3 year visa on the same day. It took me 2 months to get a 2 year visa, even though I coached him and had a far simpler case.
I have a copy of their process bible, a 1000 page PDF in thick German. I can assure you that they don't follow what's in it.
Visa process is some of the worst beurocracy in any country, since people using jt are by definition non-citizen, dont vote, and have less recourse.
Often a new policitican comes in and gives new direction for very liberal interpretation of current rules. I have many years of experience with Czech and Uk immigration systems, and both are a mess, and dont really comply with the law.
What about the address registration is unreliable? Yes, you have to go in person but apart from that it's a pretty quick and standardized trip. (The appointment problem is a pretty much uniquely Berlin thing who is overworking their bureaucracy)
The vehicle processes are currently being overhauled. Vehicles can now be transferred online if the original registration was after 2015 and you own an electronic ID. More such processes will be coming shortly in all parts of administration.
It shouldn't have to be a 3 page guide, but there's enough variation in the process to warrant it. 5 years ago, just getting an appointment was an adventure.
For instance, my friend managed to do something by email. The same day, I got an answer from the same office confirming that it was impossible.
I spent months documenting the freelance visa application process, and worked with several relocation consultants to document it. A person I helped got a 3 year visa on the same day. It took me 2 months to get a 2 year visa, even though I coached him and had a far simpler case.
I have a copy of their process bible, a 1000 page PDF in thick German. I can assure you that they don't follow what's in it.