Why does SKAction consume resources?

Question

Objective-C

Why any activation of SKAction consumes a lot of CPU
Let's say that with a single action - such as moving the menu - it's not scary.
And let's say we make a background that moves behind the accelerator.
I catch the movement along the X, Y axis and then in the update block of the scene I write for each sprite

self.sprite0.run(SKAction.move(by: CGVector(dx: 100+destX, dy: 100+destY),  duration: 1))

If I set the conditions to update every 1/30 of a second, then the load does not particularly decrease. At 1/10 you can see jerks.
In the simulator, the CPU load is 100%
On iphone 8plus, the cpu load is 43%
I turn off run SKAction from update - the load goes away.
Similarly, if you run SKAction.repeatForever