What is the importance of antimatter?

[Georgi Guninski]

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?