I think that the nation of Eldia - based upon how they have been shown to us - is worthy of existing.
Too bad that is not what the author intends to do, based on the sketch of the last slide of this manga shown.
Eldia is a noble race that contains people, exceptional individuals, that other races lack.
it is astounding, how pure the message of this manga is, regarding this.
What is the end message? That noble races ultimately always die out? Maybe it is the nobility of their character itself that makes them go extinct?
Very interesting questions.