Both stories take place in a fantasy society which enforces conformity to soul damaging norms. Both stories are didactic, written to teach the reader cautionary lessons about troubling trends in our own society. But their tones differ radically.
Vonnegut's "Harrison Bergemon" is set precisely in the year 2081. Society has gone to absurd lengths to make sure everyone is "equal" and that nobody stands out. This especially means that people have their intelligence, talents, and good looks suppressed so that nobody else will feel inferior. This norm is enforced through violence: apparently anybody brave or intelligent enough to challenge the system is killed. This is a commentary on moves in our own society to "level playing fields" and give people equal opportunity. This future society, however, is so bad nobody would want to live in it.
LeGuin does not set "The Ones who Walk Away from Omelas" in a specific year. It, too depicts a society that has a troubling core: in this case, everyone...
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