What is the importance of antimatter?

What is the importance of antimatter? As is known, I don't understand physics. The front page of wikipedia links to new results in antimatter related to antihydrogen. https://en.wikipedia.org/wiki/Antihydrogen What is the importance of antimatter not counting nukes? Why antimatter is accepted by the standard model in physics, but anti-time and anti-space appear to be considered cranky topic? Could it be currently we don't have measuring devices and enough precision to detect anti-time and anti-space and the imaginary (in the complex sense) stuff from the square root of negative real in the Lorentz transformations, closely related to relativity?