Emilio, the next time you think it needs adjusting, it doesn't. If the engine isn't running right because you think the carb's not right, don't touch it. Something else is wrong. Usually the ignition.
Carbs don't go out of adjustment.
Sure they do, throttle shafts wear, jets plug among other things. Your correct by saying that the adjustment screws shouldn't move over time but if a throttle shaft wears an adjustment may be needed (along with replacing a worn shaft bushing)
A plugged jet isn't an adjustment.
Throttle shaft wear happens so slowly; maybe every few years it
might need a change. The manual tells you to put a drop of oil on the end of the throttle shaft at every tune-up or oil change. This goes a long way to prevent wear. If you make sure you don't have binding in your linkage, you won't be wearing out your carbs.
I haven't adjusted my carbs since early 2000. So far just over 100k km.
Many years ago I was brainwashed by those that didn't know what they were doing. The prevalent myth was that dual carbs are a bad idea on a daily driver because you always have to "tune" them. You always had to adjust them to keep them in sync. What a load of crap.