But it is. If the state does not legislate to allow it or to not prosecute those who assist with it, then the individual has no freedom of choice of personal end of life matters.
Unless the state allows for unrestricted assistance of suicide (which would be a moral issue), it is choosing who is and who is not eligible for assisted suicide, which is way outside of the role of government. A prohibition on assisted suicide may not be perfect, but it is the only way to avoid the discrimination and deification of government of restricted assisted suicide and the obvious moral and practical issues of unrestricted assisted suicide.
As long as the patient in question retains complete autonomy over the matter, it's quite a stretch to suggest this would be an instance of the
government deciding who lives and who dies; rather, it's whether the doctor should be prosecuted for fulfilling the desires of their patient, who of course could easily seek alternative (and arguably more destructive or ineffective) methods of suicide.