not everything in a story has to or should be "realistic" but in my opinion there's a level of illusion that should be maintained, and I think that's the actual problem that many people try to pinpoint with the "unrealistic" criticism. Dialogue shouldn't be written like an actual transcript of human speech, but should contribute to the illusion of a real person speaking. A character is a tool of the story, not a narrative, but we're trying to maintain the illusion that they are a person. Worldbuilding should exist to serve the story, not to be a perfect simulacrum of how every aspect of nature/society etc. would actually play out for real. But there should be the illusion that it could be real, that organizations and systems would operate in such a way, that people might behave in such a way.
in conclusion: "Is this realistic?" <<wrong question. "Does this serve the illusion or disrupt it?" <<now we're talking
