Stem cells could be used as a renewable source of replacement for people, rather than going through entire transplants. This would reduce the need for invasiveness in transplant surgeries, as well as ethical questions regarding organ donations.
However, using stem cells raises ethical concerns regarding embryos, because they are used for research after they have been unused for IVF treatment - alleviate human suffering, or the duty to care for human life? Many people consider the embryo the beginning of human life, so using them as stem cells is considered destroying human life.
There is also an issue regarding equity of access because of the high cost, and the consideration that these potential therapies may not be accessible to rural or remote communities.