The medical system itself, and agents within that system, including health care administrators, providers (when they are not compensated in a fee for service format), and taxpayers/insurance-premium-payers, all stand to gain if someone opts for less expensive end-of-life care, which would include assisted suicide, than if someone opted for the more expensive care to prolong one's problematic life.  That's the textbook case of a perverse institutional incentive to encourage someone to die instead of living a while longer.