So what is a class like?
A regular class has punches being thrown, kicks being delivered, swords and sticks swinging…
A good portion of the class is target practice and you are the target.
A target that is not going to be there.
The dojo is a place to learn the art, and part of that learning process is learning to undo how you move, to eventually move the body as a unified whole, using taijutsu.
Being punched and kicked, objects entering your space is not a normal part of everyday life so the initial part of the training, in a safe and controlled space, is to get you used to thing coming at you.
Building on that are body postures and footwork to get one safely out of the way, while putting one in a position to better escape or protect.
There are many things that might seem a bit excessive in the martial arts, but they are necessary to being able to move without thinking- mushin in the Japanese martial arts.