In the canon of Star Trek, humanity had a series of eugenics wars, wars for resources, and then capped it off with a World War 3 where the Geneva conventions were scrapped with nuclear, chemical, and biological weapons used by every world power.
The mess was still being cleaned up and the effects of hundreds of millions dead is when people went “Why did we ever hate each other? What did some dude in the African Union do to piss off some dude in the European Alliance, that pissed off some dude in China?”
And then when Zefram Cochrane used the Phoenix to test warp flight, everyone truly went “…Holy shit, we’re not alone. We can fix this for everyone.”
In a way, he did. Star Trek helped to break the racial barriers of 1960’s America, and inspired a generation of scientists and engineers to invent things that we use commonly today.
There was an entire generation of people who saw what Star Trek brought to the TV screen, and wanted to bring it into reality. Gene saw thousands of fans were inspired to become a better person because of an idea he had one day.
People saw an interracial kiss on screen for the first time. Some were outraged, most didn’t see a problem. Some saw a Japanese person working equally with white crewmen while Japanese-Americans still were treated like garbage and had their possessions still stripped from them.
Gene didn’t live to see a post-scarcity, no violence, bigotry free society, but he inspired people to achieve it. Gene died happy with knowing he sparked an entire idea into action, some day in the future.