Let us all save our money and buy a MF and shoot landscape at f/2.
I agree with most but not really with this paragraph. Appropriately scaled (same) great quality lenses just do not exist. You cannot scale the index of refraction, and the lens design must be different. For the same DOF, etc., you have rays which need to be focused more than before (for smaller sensors), etc. There is a reason MF is still alive. The FF resolution near, say, f/2 is dramatically better than the crop one at f/1.4. When you stop down, the advantage decreases but it is there, and is real. I never had a landscape with my crop cameras that I could find acceptable, with all kind of lenses, L or not. Now, even the 24-105 is clearly better.