Like in Brazil, where there are real cases of people convicted of murdering donors to sell their organs to rich people?

Third-world country edge-cases. Murder is still murder. The preponderance of donations in first-world countries saves lives, but is so rarely done despite the pressing demand. When you or family member needs a life-saving transplant, which system would you want?

The one where the organ was freely and explicitly offered, not harvested from a person who might have mistakenly believed their body would still be theirs in death.