This comment is very black and white for a complicated topic. Personally I think people should have the right to die in a carefully regulated and administered fashion, after they have received appropriate counselling and support. The support is essential. However in real world application there are only relatively few cases where euthanasia is arguably the 'best' option. I am very much at the coalface of this issue if you are concerned I am an armchair commenter.

Doctors and nurses don't generally euthanize people. Pallative care are actively against the concept and do research showing that various strategies for symptom management do not shorten life. If someone is suffering a lot from pain or shortness of breath, they will receive escalating doses of drugs which can cause death, but the reason for administering them is not to cause death. The distinction is important.

When someone is suffering a lot, they should receive good symptom support and unnecessary investigations and interventions should be avoided. This means that all the blood tests, blood pressure checks, X-rays, nutritional support people would normally undergo don't get done. Is that a form of (perfectly legal) euthanasia, if an easily correctible but otherwise fatal problem doesn't get fixed?

There are underground euthanasia practitioners for sure. These are doctors or nurses who take it upon themselves to administer fatal doses of medication to people who want to die. Invariably this is done at home. I've heard terrible stories about when it goes wrong.

I live somewhere where there is legalised voluntary euthanasia or assisted dying as they call it. Patients go through a process where they are assessed by two doctors (who have been trained specifically) and then when it is approved they receive medication they can take themselves. It works well generally. But is not a fast process. Patients with cancer certainly die during the process. And they don't die in agony. Modern palliative care is excellent, if you live somewhere where it exists, particularly for cancer.

The part missing from your analysis is that the health care system has limited resources, and properly assessing patients for and administering euthanasia takes a lot of resources. It is not much of an exaggeration to say that it is easier to die than to see a psychologist where I live. The doctors who do the assessments are not seeing other patients. The money used to pay for the assessments etc is not being spent elsewhere (it's a socialised healthcare system). Even if the patient pays for everything, you are still using up time and expertise.

The 'easy' cases for euthanasia are people with degenerative neurological conditions where there is no treatment available, just gradual slow descent into disability. Cancer is more complicated - patients can be very well until close to the end, and they are often having ongoing treatment. It is hard to be considing euthanasia while hoping the next clinical trial will work. Cancer patients also tend to die quickly.

For major organ dysfunction like heart failure, kidney failure, liver failure, it is possible to withdraw active medical support and therapy and patients will die fairly quickly, while also receiving symptom support.

Euthanasia for mental illness I find would be almost impossible to implement. Euthanasia for chronic pain I think would also be very difficult. Euthanasia for dementia has obvious problems too, although we all tell our partners to push us off the pier when we can't do the crossword anymore.

Some people just want to die because they are too old, fed up etc despite no
serious medical problems or overt mental illness. I don't know about this. I am not sure a medical system can support this kind of choice, it is 'out of scope' to my mind, a kind of medicalisation of the human condition. There is a complicated spectrum from 'Completely well and wanting to die' and 'Severe imminently fatal illness and wanting to die.'