>A lot of German primary care doctors don't even hire office staff.

I have never been to a German doctor who didn't have some staff. It's true however that they usually do not have admin-only staff.

They have, depending on the size (and specialty) of their operation, 1-3 "Medizinischer Fachangestellte" (MFA, qualified medial employees) per doctor and maybe 1-2 "Auszubildende" (people still in training). This a qualified job which requires formal training and a diploma. Usually it's one person in charge of the appointment book and reception/waiting room and additional people helping the physicians.

They are helping during examinations, calling up people from the waiting rooms, keeping appointment books, keeping the patient files and printing out the prescriptions etc (to be signed by the doctor), and to some degree interact with the health insurers. But they also do some hands-on jobs, like they are usually allowed to apply some medications, and operate medical equipment on their own (e.g. last time I visited my dentist, the x-ray machine was operated by an MFA; she had to have a special qualification for that). They are also in charge of writing the invoices for procedures not covered by health insurance providers (e.g. additional checkups).

My GP is a single lady shop, and she hired 3 MFAs. My dentist shop has 3 dentists working there and one "technician" and has an MFA support staff of maybe 15.

So there is still a lot of admin work, after all.

>They prescribe whatever they want

Not exactly. German doctors prescribe an "active agent" (even tho a lot of times they will put a brand name). German public insurers will only pay for a max price for a given agent. So if "generics" are available, the pharmacies will likely fill prescriptions with those.

>swipe your medical card

Eh, you give your card to the doctor's MFAs and they will put it in their card reader, etc. It's not like there is a checkout line where you swipe stuff yourself.

>they're guaranteed to be paid in a week

Usually one month to four months.

It goes like this: Every physician has to be a member in the "Kassenärtzliche Vereinigung" (KV, physicians association, and KZV for dentists) of their federal state. Otherwise, you cannot be reimbursed by the public insurers. There is about 160k physicians and 60k dentists organized in the KVs and KZVs.

The physicians then report all the items (procedures, prescriptions, consolations, etc) they want to charge to the KV, which collects the information, tallies up everything and calculates the earnings based on a complicated "points" system, charges the insurers and distributes the money back to their members.

The physicians are paid once a month (usually the 15th of each month for most KVs) a progress payment, based on the estimated earnings for a quarter, estimated based on previous quarters in particular. The actual final tally is done only once a quarter where any money not yet paid through the progress payments is paid out. In the worst case, this could be a negative number, meaning a physician has to pay back some of their previously collected progress payments. That's why (AFAIK) KVs will usually underestimate the progress payments to avoid exactly this later.

>no questions asked.

The KVs will totally ask questions if your doctor starts billing a lot "funny" items (e.g. if a single doctor would charge a lot of flu vaccinations during the summer months, the KV will ask about it). And last I heard, there are spot checks/(not-so) random audits too. The KVs by law are required to make sure everything is OK, so they also dabble in fraud detection and quality control.