Moments ago, I, too, used to think this way, but then I glanced around at the comments here, and I realize that even if immortal, we'd still have to suffer each other, and that simply just can't go on forever.
I disagree. We absorb pain for our community/tribe or our own goals. Ideally, we don’t pass it on.
That resonates with what you said - if we could absorb violence and not pass it on we can contain it. Unfortunately, the western world handles violence with more violence, which is the same as throwing a sick person into the village well.
It kind of reminds me how Fox News selects its presenters. They’d definitely be the ones a sane society would try to punish.
I wonder if it has to do with the fact that your current lifespan is "natural" and an immortal lifespan is "unnatural". But what's the difference between being alive in 10,000 years, and being alive currently? A person 10,000 years old may believe themself to be immortal but there's fundamentally no difference between being "currently alive" at 10,000 and being "currently alive" at 40. Either way, it's an experience of the present. So what makes living to 10,000 wrong, if living to 40 is right?
If there is no death, there will only be more suffering, as suffering is in human nature. We experience pain, and want to return that pain.