Cryonics and life extension are both technologies in different stages of development. Both are basically medical technologies. Cryonics aims to freeze legally dead humans so they can be brought back to life at a later time once medical technology improves significantly. Life extension technology aims to stop and/or reverse human aging so that humans can live dramatically longer, and perhaps indefinitely. Humans are already being frozen upon legal death.
There are at least two organizations that are cryo-preserving humans after legal death. One of them is the Alcor Life Extension Foundation. Life extension technology is not nearly as progressed as cryonics technology, at least relatively speaking, it seems. There are some scientists who are working to stop and/or reverse human aging. Aubrey de Grey is one scientist working to develop this technology. He is a biomedical gerontologist. Hopefully these technologies will be developed as fast as possible.
There are quite a few reasons why life extension and cryonics are good potential technologies. Disease is bad because it kills humans. Aging also kills humans, so it is also just as bad as disease. Aging is mostly different from disease in that it so far as always killed human life. It is possible that these technologies may never be workable. However, this has not been proven. It is also true that these technologies might actually be quite possible, and that with the proper funding and research done, they could be developed into fairly mature technologies relatively quickly.
Hopefully more humans on this Earth will work to develop these technologies, and will also support the development of these technologies. There is privately funded research going on. Perhaps in the future, enough citizens will mobilize around these technologies so there are can be government funding which could likely be more plentiful than private dollars it seems. Hopefully sooner, rather than later, humans will not have to experience the loss of their fellow humans.
It should be noted that no one should be forced to live indefinitely, and all adults should at least have the option of ending their life whenever they would choose to let it or make it happen. Each human’s body should be considered their own property, and not the property of any government, family member or anyone else. So, cryonics and life extension technology are quite good, and more individuals should support and conduct research into these two technologies.