CBeck113, is right on the money. Seeing the edge of your own car gives you a reference point and is also an important view when driving in reverse that requires you to maneuver into a space. Then seeing the the edge of your car gives you the reference point of knowing you won't hit anything with it when you're maneuvering i.e. into a parking space at the side of a road.
I'm actually dumbfounded that this is actually a discussion.
Andres wrote:And you´re moving your eyes away from the road, wich is far from optimal
Welcome to driving on the road. Moving your eyes away from the road is a necessity at times because it's impossible to have a complete view of what is happening around you. There's a reason why driving schools teach the method I've described, because it limits these moments to a minimum and only when required (i.e. changing lanes).
The method you are proposing is dangerous because your view from the center mirror is very
limited and inadequate. For one, you are looking through a very narrow space between the two driver seats and through a window (that might even have sun blinders on). That view is completely obstructed once you have a larger vehicle driving behind you, hence it is impossible to see what is happening on the lanes parallel to yours to the rear, i.e. on the Autobahn.
With the mirrors correctly adjusted (in my illustration), you have a complete view of your side lanes to your rear through both side mirrors by just glancing at them with your eyes. The view in that angle towards the rear also gives you a fairly good indication of approaching vehicles on parallel lanes and their relative speed (because their velocity can be gauged and quantified given the angle), even if there's vehicle right behind you.
The blind-spot is there yes, which is why approaching changing lanes or direction changes under the 3 steps I described is essential and taught in every single competent driving school. In most countries, not doing these 3 steps will result in not passing your drivers exam. Not turning your head to quickly check your blind-spot is a guaranteed accident and akin to walking over a road without looking. It's daft, stupid and dangerous.
Even if we entertain your method, by pointing the side mirrors outward, you are limiting your view and what is happening at the rear by a very narrow limited view through the back window and if there is a vehicle there, you will be blind, meaning to actually attempt changing a lane on the Autobahn, will mean you will have to move your head far left and beyond the blind spot to see if something is coming on the parallel lane from behind at high speed. The time to do so will actually be significantly longer and thus far more dangerous than if you had your side mirrors correctly and only needed to check your blind-spot to make sure nothing is there.
My advice; drive on any meaningful Autobahn, extreme case, in Germany, where you might be stuck in a lane with cars in front and behind you at 100kmh and might be facing cars coming from behind on the fast lane at excess of 140kmh. Seeing those cars in your side mirrors properly gives you an indication if that is the case and what their speed is (as you can trace their movement by just glancing at the mirror, while your peripheral view still sees what is going on in front) and if and when it is safe to move out (not before checking your blind-spot with the mandatory quick glance though).
Note: I took the image from Jefs URL and added the correct side mirror angle (green), as well as added a car coming from far back at high speed, while also adding a car that is obstructing your center-mirror right behind you. A typical case on any typical slightly congested motorway. The gap might be exaggerated slightly (a cars length) but isn't too uncommon. If I wanted to make the point more extreme, I could have placed a truck there.
Anyway, the illustration speaks for itself. If you had the red-view adjusted side-mirrors, you wouldn't see that car approaching at high speed until it literally blizzes past in your mirrors and then windows. Good luck pulling out of your lane then without spending much time desperately turning your head to glance back (just falling short of actually sticking your head out the window to look back
The only scary thing I can note about moving the mirrors out towards the blind spot is that its leads people to not turn their head at all, making them believe it's actually safe to drive by just glancing at your 3 mirrors. In my country, driving like that (and provoking a dangerous maneuver) would likely mean a loss of your drivers license immediately and for good reason too.
It's actually scary to read stuff like the above URL. Then again, given I drive around 30'000 km on the roads annually (since over 15 years), nothing surprises anymore sadly...