I lost my dad recently (he was 84 and lived a wonderful and healthy life, which I consider a huge win for him). He had a terribly bad stroke that left him very much alive, but without the ability to speak, read, or write. He was a professional book reviewer and writer for much of his life, and continued to read, write, and think with voracity up until the minute before his stroke (he was setting up his Series 4 Apple…
The goal and ideal scenario is that when circumstances require it, your loved ones do not feel that they are the ones making a decision. They should feel that they are carrying out the decision that you already made for them, with minimal interpretation on your part.
I was in a similar situation with my mother, and without going into too much detail, it was a significant burden taken off of me that she had made it very clear (both in person over the years, and through legal documents) what her wishes were. It is honestly something that I'm very thankful that she did, and recommend to others, especially those facing eminent medical issues.