Why is driving with a foreign driver's license generally accepted on short vacations? [closed]

In most countries I have been to, I was allowed to drive with my german driver's license if my stay was below X days (often 90). Vice versa, many people coming to germany and other countries seem to be allowed to drive with their license.

Why is this allowed?

I asked myself this, because I see some obvious CONs here:

I know the obvious reason is that you just cannot expect people that come for 3 days to obtain a local driver's license. But then, maybe the correct solution would be to not allow these people to drive at all.

During my theory test, I had to remember all road signs and a lot more details (how far from a crosswalk are you allowed to park, how do you have to secure payload that is longer than your car, and so on). If I would have failed in three questions, I would not have gotten my license. In contrast, foreigners cannot know these rules, as they differ by country. Thus, they do not seem to have the theoretical knowledge required to drive a car here. One can now of course argue, that these details don't matter anyway in day-to-day traffic, and they are probably right. But if they don't matter, then why should I know them during the test after all?

Another example: Driving on the right versus driving on the left. I was totally allowed to drive a car in Australia. Yet, I was close to triggering an accident, as I was just not used to driving on the left and having to leave a highway on the left. I was a high risk for everyone around me. Yet, the authorities don't seem to care about this.

Of course, the obvious PRO argument is:

It just makes things easier for tourists.

Why are these problems not a concern for the authorities?