Apologies as this is a litttle off topic from OP’s post, but it seems relevant to much of the discussion.
I was recommended this document by a friend’s father who’s a leader in the hospice movement:
“Five Wishes is a United States advance directive created by the non-profit organization Aging with Dignity. It has been described as the "living will with a heart and soul".”
https://en.m.wikipedia.org/wiki/Five_Wishes
It’s an excellent document that I’ve shared with family and friends. It’s particularly useful to get something in place (easily and compassionately) for those that don’t have a living will.
Even better, here in the U.S. most states have their own model health care POA form(s).
You can explicitly spell out exactly what kind of treatments you want (or, more likely, don't) and pick someone to be your health care agent, who has full legal power to make health care decisions when you are incapacitated.
I've said this before, but I had a parent who developed an unusual form of dementia that typically strikes between ages 45-55.
They were diagnosed around age 50, dead around a decade later, most of that time bed-bound, requiring total care (feeding, changing, bathing, etc.)
Not surprisingly, they suffered from repeated infections. The only reason they lived so long was that I didn't put my foot down and insist they be put on Hospice instead (obviously, it wasn't a situation explicitly discussed in their health care POA)
Given the above, my health care directive is extremely restrictive, e.g. no antibiotics, period, if I have dementia.
So I'm not worried about being stuck for a decade in a nursing home.
You are in control as to your health care preferences, whether you want a full-court press or just Hospice or something in-between.
Please be as specific as possible, don't make your loved ones have to guess about your treatment preferences.