Sadly there's still some prohibition on giving the patient enough to comfortably OD and voluntarily end their suffering in a lot of places. I've heard nurses say that they're instructed to try and keep the patient optimistic, even when all that life means to them anymore is continued suffering. Gotta squeeze every last dollar out of them or something I suppose.
There is a less cynical explanation: if you make it too easy for people to kill themselves then you run the risk of old people being coerced into taking that option by, for example, greedy relatives eyeing their inheritance.
And it could be seen as a perverse incentive for governments to make it too easy for people who are an economic and budgetary burden to end their own lives.
I believe this approach is also present in the UK where the patient isn't paying for their treatment directly. So I doubt it is to do with making money.