Maybe there's a distinction to be drawn between "inherent part of the human condition" and the "default state", as you have described it. Attempting to change something "inherent" seems worthless, but default is merely waiting to be overwritten with something better.
For ex: death is inherent in the human condition, we cannot avoid it and must deal with it. Nakedness is only the default state, and is pretty easily solved.
Back to economics: maybe scarcity is inherent, but "social tragedy" may be merely a very solvable default.
But keeping appropriate timescales in mind, I agree with the conclusion - for given constraints, there are things that are inherent and not worth attacking, and then defaults that are merely attractors for the system state.
Should? You're assuming that mortality is a problem. Extreme longevity or immortality would certainly change the human condition, but it's purely speculative to think it would be better in some objective, widely-accepted sense. Not every "default" is something waiting to be fixed.
There's a good argument to be made that the assumption of mortality is baked into so many things in our economy that it would break down if people suddenly started to live much longer on average. But that, again, is a default - some state attractor. Something we can try to work around.
As a speculative anecdote, imagine spending ten thousand years missing a child who died in an irreversible accident. (Would childbirth even be permitted in such a future? How would overpopulation be addressed?) Or the dampening economic and sociological effects caused by a millegenerian population's entrenched resistance to change. Or the possibility that longevity is only available to the wealthy, or the drudgery of being stuck in a boring job for millenia...
Longevity doesn't necessarily solve sadness, suffering, and social ills -- it just shifts the goalposts.