If God loved animals why have animal sacrifice?

2 questions!! 1. In Genesis we see he created animals and they were wonderful and he wanted us to take care of them. We sin and animals pay the price over and over. My thought was this is because he expected us to love them so much and it to hurt us to watch them die because of our sin … teach us a lesson. Then he makes so many rules about animal sacrifice and it gets more common. Why? As God he could’ve had something else be atonement. 2. If they are sacrificed to God… they are his… I would think he would want their soul returned to him because he loves them so much. Jesus died as a sacrifice and returned to him (I know I know totally different). Any insights here to share?