“… their metamaterial, fabricated from a common titanium alloy, proved to be 50% stronger than the strongest alloy of similar density used in aerospace...”
They didn’t create a new material, they developed a stronger share to more evenly distribute stresses.
Exactly correct.
When they get down to the atomic level (nano-machinery, we are working on it), much stronger materials in all dimensions are possible because we will be able to eliminate the atomic/crystalline level flaws which we can only work to minimize today.