You actually have a great point.
But it seems that many human beings reject the idea of a utopia as "boring." Other analyses say that the idea of a utopia is distinctly discriminatory (because in order to be a utopia, it always has to exclude someone). We see this play out in real life via xenophobic impulses.
The idea of a utopia held a lot of sway in earlier eras. But in contemporary times, artists and thinkers seem to be more interest in interrogating, critiquing, and problematizing them. Ursula LeGuin did in
"The Ones Who Walk Away from Omelas." Toni Morrison did in
Paradise. Marvel is currently doing it with Wakanda--
which is also annoying some fans. And clearly DC has been doing it over and over with Themyscira.
I think that it points to a particular lack of imagination. If readers crave conflict, it seems clear to me that the Amazons can have it vis-à-vis the gods, demons, and outsiders.
But to DC's defense, utopias don't just materialize out of thin air. In order to
attain a utopian society, a lot of bloodshed is necessary beforehand because everyone who wants to be a part of it might not have the best intentions and you have to find a way to weed them out/exclude them and that inevitably leads to some kind of war.
Then again, these are comic books and those concerns can be completely ignored for the larger purpose of depicting a utopia.
Unfortunately though, the modern reader would be suspicious or bored, and tune out. And at the end of the day, these publishers are trying to sell books, so for better or for worse: Game of Thrones Amazons it is!