Why in ancient Egypt for the theft of things, cattle and a slave were punished in the same way?

It is very simple to explain everything here. The slaves had no rights, they belonged to their master. Were the same as other things or animals. Sometimes even livestock was more valuable than slaves. So, if the slaves did not have any rights, and they were just property, then it is logical that the punishment for theft of any property was the same. Stealing a slave in Egypt is like stealing now, for example, a tractor. But slaves for theft were punished very cruelly and indicatively, up to the death penalty.