I'm French, so I can give you a point of view. I think people are in favor of euthanizing elderly people but in no way for mental illnesses, psychological suffering, or for young people who have incurable illnesses. And assisted suicide, let's not even talk about it. It is very common in France that the wishes of the dead are not respected, in particular on the cessation of treatment, the refusal of care (which is comparable to eutahnasia). There was a very famous Vincent Lambert case, to give you an idea of French jurisprudential actions. To summarize, a man had a serious accident and ended up in a vegetative state. Being a cripple, he had always said he wanted to stop all treatment and all artificial life support if he ever found himself in such a situation. His wife therefore asked that he be "unplugged". The family strongly opposed this, saying it was wrong, he didn't really want this, he shouldn't be killed. It remained in this vegetative state for 10 years. The family has seized all the existing jurisdictions: French, European...
The laws on this subject exist but are very recent and are not really applied. Make no mistake, France is a conservative country despite appearances. And every year this debate resurfaces in the press, but there is no question of legislating the issue immediately at least. It's like the legalization of cannabis, much ado about not much. I doubt cannabis will ever be allowed.