The G&M would not print what I feel like writing so instead:

99.9% would probably improve......

You know nothing of what you write.  It's not some anonymous state that makes the decision if a very ill individual will be given an OK for a graceful assisted death.  It's a board, it's doctors, i's
people who has made it their lives' work to do good.  When they see such suffering they know when and if it's time to say YES. 

Look at the suicide figures for seriously ill people.  Physically and Mentally.  You probably have never known anyone who had to go that route.  Try doing some volunteer work on a suicide
prevention line and you will learn.  Or look around, volunteer in a psychiatric hospital or day centre. Read the literature.  
All illness cannot be treated.  Far from it.  Why do you think people die young?