We cannot stop a person from doing something evil?
we can say things and yes try to stop a person doing evil, but a person trying to kill themselves or have some one help them kill themselves is allowed to make their own choice. Each person answers to God for their choices. It’s not a joint judgement session with your friends or doctors and God. Each person makes their final choices in any matter any day of the week.
Those assisting in doctor assisted death are assisting in evil for sure.