getting pretty technical here, but there are some different aspects of "strength" properties, and various temperature effects to compare under application conditions. But the simple way to address this is to consider the strength/weight ratio.....
one of the possible achievements in material science is in the class of composites or structural modifications. The new steel is a product of such an effort. I wonder about what we can do with micro-engineering or casting technologies that produce structures like honeycomb with gains in the strength/weight ratio.
Mg, Al, Fe, and Ti are very abundant elements. Mg, Al, and Ti metal is expensive because of the electricity required to produce the metal from the oxides, or the salt in the case of Mg. If we had nuclear power plants co-located with these metal reduction plants..... and MSFE desalination plants as well, it would cut costs not only with cheaper electricity but synergistic efficiencies in utilizing waste heat and producing by-product industrial chemicals.
Lithium is going to be a by-product of any Magnesium operation. So here we have the potential to really make electric cars economical. . . . .