The leading causes of death are diseases, cancers, dementia, road injuries, etc. These are inarguably more "horrifying" deaths than how we could kill people with methods such as those used for euthanasia, which is the point the original comment was making.
If a human has no friends, and their death would not bring great and lasting sadness to other humans, is it ok to murder them?
If a human is mentally or physically incapable of improving the lot of other people, and is in fact a burden on society, is it ok to murder them?
A minority of people are caused distress by having their children vaccinated because they think vaccines cause autism. Should we stop causing suffering to this minority by stopping all vacciantions? Or is it ok to cause suffering to humans who are minorities because they are minorities?
When people choose not to be vaccinated, they endanger those who are unable to be vaccinated. Foregoing vaccination harms others.
The normalized consumption of animal products endangers all people due to the impact it has on the environment in which we live. We are currently living through yet another pandemic caused by the consumption of animals. We are currently dealing with the effects of climate collapse worldwide, helped along by inefficient resource usage for things like animal agriculture.
Consuming plants instead of animals is a trivial change to make both at the individual and societal level and does not harm others.
If a human has no friends, and their death would not bring great and lasting sadness to other humans, is it ok to murder them?
If a human is mentally or physically incapable of improving the lot of other people, and is in fact a burden on society, is it ok to murder them?