I became critically ill in 2012, and despite good mental health improvement since then, I remain physically weak, and essentially bed ridden. Early in this process, I was unconscious and my wife made several decisions that kept me alive. When I recovered physically, I was still mentally ill and unfit to make reasonable decisions. Again, my wife--in conjunction with the medics--made all the decisions. I survived and then improved mentally over time.
Do I appreciate all this? Not always. We do enjoy several aspects of our new lives. Others, I certainly don't. I don't like what I've become, essentially a highly dependent cripple (my own label). As things deteriorate from here, I'd like to have control over the timing of my death, unless I did naturally before I'm desperate to go!
It would upset my wife to discuss this. I doubt I could end things without her help, and some medical help. What decisions might I make alone? No important ones!
Sorry, but I got a bit sidetracked! A perfect representation of my current condition....
I guess my point is that when you want to be left to die, you're likely to be too ill to manage it alone. In this type of extreme case, your question makes little sense.
Things also depend on relationships with family and medics. I was refused one hugely important course of treatment at my local hospital on the grounds it would be too dangerous for me. Later, I was put under the care of a consultant for a different important matter. My wife and I deemed this man incompetent. In both cases my wife pushed for second opinions. We now deal directly with three distinct specialist hospitals of international renown. Thank goodness! I couldn't have done this alone. And the medics actively sought to discourage us. You really need to know who to talk to, about what, and when.