Xi Jinping knows how China is extending the lives of elderly CCP members. They use forced organ transplants from Falun Gong and Uyghur prisoners. The problem was that this supply of organs created political issues when the world found out about it, so the PLA developed methods to transplant organs from babies that were bred with the genetic material from the intended recipient. They also breed babies for their stem cells to replenish platelets and other blood products from ageing patients. Here’s a link to a website by a Chinese expat who reads the Chinese press reports that Western sources don’t follow. https://youtu.be/jaCpQfm6yNE
Organ transplants might extend a life that was about to end suddenly. However long term a transplant patient has a shorter life span that someone who never needed a transplant.
Getting anything transplanted into you is a huge body stressor, let alone several organs.