Euthanasia is controversial for a lot of reasons. Some people worry that authoritarians will use it as a way to "purge" or, such as here in Canada, as a way to "reneg" on health care obligations that tax payers are paying for. Others worry that family members and care providers will abuse the law for financial gain ("legal murder" for inheritance etc.).
Then you have cases like this one: https://www.cbc.ca/news/canada/calgary/calgary-maid-father-d...
It's complicated because we're not talking about an elderly person with terminal cancer. We're talking about a 27 year-old high functioning adult who sought, and was granted, medical assistance in dying due to a mental illness. When you dive into that story, even if you agree that the courts made the right decision and that the 27 year-old had the right to decide her own fate, your heart can't not break thinking about the father.
Morally, I agree that every [adult] individual has the right to commit suicide by any means of their choosing (as long as they're not infringing upon the rights of others in the process). That doesn't mean that there aren't valid reasons for people to debate whether or not ehutanasia should be legal and under what circumstances.