Agree. Immortality would be a tragedy of the commons, in my opinion. At least, in an environment with limited resources. If we were capable of interstellar travel and there was no other life out there it wouldn't be, but until that happens its ultimately good for society that it has a complete turnover every hundred years, and not just for evolutionary adaptation. Imagine if Stalin or Mao had never died. Imagine if the entire British government was run by politicians from the 1300s to the 1800s. Maybe Caesar Augustus would still be running the Roman Empire, fighting a never-ending insurgency from the prophet Muhammad.

Things might have more stability, but change and opportunity would hardly exist and each succeeding generation would be permanent underclasses of children.

"A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it. " - Max Planck