Expensive, wasteful spending to unnecessarily extend lives should be left up to the individual on a "pay as you go" basis. Pay as you go - and, when you stop paying, it's time for you to go.
And here's the problem with your "compassionate" (not) answer. Who determines "old"...who determines what's a "miserable" life, and who determines what's "unnecessary?"
Most people can spot "old" just like they can spot "pornography."
Like I said, I think all of these decisions should be left to the individual. As long as they keep paying, keep treating. They will let you know when it's time to stop because they will quit paying. That's "what pay as you go" means.
The Lord is waiting for each of us. Trust Him.