If I may add...

People can be coerced into euthanasia. Or just bullied into it. For example. If someone is non heterosexual and is outed into a very conservative society, they may be coerced into taking treatment to be "cured from homossexualism"
Having their mental health damaged in the process. This, of course, is the main purpose of such "treatments". And suddenly you have a situation similar to concentration camps in which you drive "the undesirables" out of the society, in a "fit in or euthanase yourself" way. In a way robbing them out of their autonomy and still playing the good guy.

The same would be for elderly people. Except the emotional blackmail would come in the form of "think of your family, they would be better off without you, you had your chance"

This would empower people in social darwinism and drive a big prob of the society into openly embracing it.

However.... I'm still in favor of euthanasia. These points I mentioned, are not to be underestimated. I recognize that I'd have been coerced into euthanasia years ago.

I still consider it, but to which point it is my will? How much is society pressuring me to euthanase myself? It's hard for me to determine.