I think “show don’t tell” in fiction writing is such a difficult skill to learn because you can’t show everything, just as you can’t tell everything. it’s not about choosing one over the other, but knowing what you can show through the telling. if you’re writing first-person or third-person limited, for example, it’s not always bad to directly tell the audience what the character genuinely thinks (using their voice), because doing so suggests something else about them that the character isn’t aware of. that’s different from spelling out the implications of their beliefs, which would be considered poor form. or why they believe what they believe, revealing their core flaws and why they need to grow (stuff to show, not to tell).
the key is to differentiate what you know (that normally shouldn’t be inserted in the prose) from what the characters know (that should be made clear). and sometimes description is a bit like this too. there are some things you need to be explicit about otherwise the writing gets too vague. but there are other things you can’t say outright because it sacrifices immersion and stops your writing from creating the mood you want to express.
my point is I don’t think showing and telling are separate things. I think they work in tandem to allow for inference. and it’s really hard to master!
