Lab animals don't just run around. If they escape, there's a serious problem in the research facility. Their teeth are only a concern for the researchers working with them.

Everyone would be happy if we had an easier model than animals. If organoids could give us all the answers we get from lab animals, all the scientists would be happy. Not only would it get rid of many ethical issues (and associated administrative), it would also be cheaper. Sadly, it's not the case and we cannot effectively replace lab animals by other model systems. Not for many applications anyway.