As Writers, the "show don't tell" mantra gets chucked at us more than any other rule. Nothing, not even "no head hopping", can stir up such hellfire and fury. So, what is it about show that's so important?
For readers to care about your story, they need to be able to engage in some way. It doesn't mean you can't have an interesting work, or a fun or terrifying one, but there's just no way readers can become engrossed in your book without lots of show.
Think of showing as the beads of your story, and telling, the string. You need both in order to have a functional, beautiful work, like a homemade necklace, but the showing is what is meant to dazzle, while the telling merely holds everything together. Too much telling will always leave you with a dull, tangled mess.
Tell should always be an underlining, barely noticed thing. There are times to definitely use it. Tell can bring clarity to the show, trim words if you're in a dangerous count zone, control pace and sum up what's not worth showing, like a detective getting nowhere in his investigative questioning; including all those scenes is just not important.
Show reveals character, makes your work more colorful and visual, puts readers into the story and helps them to identify with characters. So, use it for the most part.
Like, think of ways you can show your character has an Ivy league education, loves sports, hates her mom, is persistent, is an emotional rock, has idiosyncrasies, works well under pressure, is tensing up in that traffic jam, is quirky, maintains life-long habits from living as an exchange student in Japan for one year, is suddenly afraid.
Relying on tell to reveal those kinds of things is lazy and nothing will make your work more dull and lackluster.
If critters are complaining that your characters don't seem realistic or engaging, too much telling is likely the culprit. Come on. Even a pumpkin-headed horseman can be realistic.
If you want readers to become engrossed, for your characters to come alive, for your story to be gripping, your work needs plenty of clunky, funky beads. What's so special about a necklace that's predominantly string? Not much. There's nothing wrong with some tell every now and then, but it should simply support and hold everything together. Never let tell overshadow or steal the show. Put tell in its place.
~ Signing off and sending out cyber hugs.