I see no point in an immortal existence. I finished all my business, I achieved my goals, I traveled the whole world, I created a family, I lived a good life and I can die, so that again the soul is embodied in a new body. The new body will have to learn everything from scratch.
With the current life expectancy, it seems to me that people have little time to succeed. Moreover, diseases and accidents contribute to their fate. I want to live longer, not to get sick and not to suffer from pain all this time.
To that end, God gave them so little time to work on themselves more. Some manage to succeed at a fairly young age, and others and several lives will not suffice. I think it's not a matter of longevity, but in quality for which we are responsible ourselves.