This is an extremely difficult question to answer. I think people have the right to do what they want with their own lives. But they MUST take into consideration , the feelings of their friends and family.
Some people have been mentally or physically hurt so severely that people around them who have hope for them could never understand their pain. And although it is always good to hope for life and recovery, in some cases the pain may be too great and they will live in extreme torture.
The following is very graphic and NSFW. Do not read on if you are sensitive and may be distrubed by certain content.
Here is the case of Hisashi Ouichi (https://icantbelieveitsnonfiction.com/2018/02/14/hisashi-ouchi-and-masato-shinohara/)
After reading that , an extreme case what do you think?
People should always try to be brave, if not for themselves for the ones who want them to survive and who depend on them. They should hang on as long as they can.
I believe in hope and to be optimistic as well as to help no matter what but in the end it should be up to the person to be the judge of his or her own life.
This is just my opinion