A lot of people don't realise how bad illness, especially in old people, can leave a person without experiencing it.

They have an image that it will be used on their grandparents who are still up and about living life prety well and they revolt at the idea someone would euthanized them.

However if you have any experience with illness like say severe dementia and just some old frailty you realise some people are just existing and in pain not knowing why or having the ability to do anything about it. These are the people that it would actually be a benefit to end with at least some dignity left.

For context family going through it right now 96 year old doesn't know who she is, has no control over her life, can barely speak, constantly soiled herself, doesn't do anything but eat and sleep. It's heartbreaking to see but you can't do anything.