That is not necessarily true. There are lots of instances where a specific organ is experiencing failure and could be replaced and the rest of you is pretty normal functioning. Especially in kidney failures or injuries, liver failures or injuries, and hearts as well. Think about all the people on dialysis. Lots of them are awaiting a new kidney from a donor. What if, instead of waiting 2 years for a match they grow you a new one in a few months? Same thing with the incredibly regenerative liver. Hearts might be another story, not sure there. We'd probably need to be able to grow those completely outside the body first.
