So this is a good question, and I think there is some room for some discussion on this here.

I think mainly you need to look at how teachers approach this subject. At the early levels we do need to stick a bit to narratives. This does create some issues as it does simplify "history" to the point where a lot of people think that just telling the stories is what historians do, when in reality we just call that class "history" for simplicity's sake. Because what historians do is far more complex, and we try purposefully to avoid narratives and story-telling.

But this method is effective for younger kids for a few reasons. 1) It's simple. To compare it with science, it's a popular meme, but there's a reason people still remember things like "mitochondria are the powerhouses of the cell"; that's effective teaching. Some kids are going to want to go "okay, but what does that actually mean, what's actually happening?" and learn more, but for the average person with no real desire to learn more about cells beyond the requirements this is ensuring that kids have a basic basic basic understanding.

So in comparison to history, we might say "Ostracism was a practice in Ancient Athens created by Cleisthenes in the late 6th century that allowed the people to remove politicians that they saw as dangerous which began in the early 5th century."

Anyone familiar with ostracism at an academic level would immediately go on about the weaponisation of ostracism, how it did pretty much nothing to help the Demos, and that its origins (while still more firmly in the Cleisthenic origin/Hipparchos camp) are murky when we take into account the problems of the fragmented statement of Androtion compared with that of Aristotle and the whole τοτε πρωτον debate.

But you've lost most kids, and most undergrads, at that point. That's point 2 about why narratives are good, they're a bit more accessible for everyone. If a student shows they're really keen on ostracism and really interested in ancient Greek and historiography and want to learn these things it's easy enough to open up and start going "well, it does get a bit complicated, but..." and scale up the lessons. But if kids walk away at the end of the term knowing "Cleisthenes. Ostracism. Athens. Politicians sent away" then that's a win.

And this is visible throughout most podcasts, most youtube videos, and Popular Histories. People tend to want the story told to them, and then allow themselves to branch out if something in particular piques their interest.

And after a long winding rant which ironically boils down to "get to the point, you'll keep people more interested in that way" I'll do so. The point being that you can still teach your kids the truth, and not hide the dark parts of history from them. But also you want them to be engaged, and you want them to learn early to start exploring, to start questioning. If you tell them a bit and they just respond "okay" then leave it at that. But ask them if they have any questions, ask them what they think, get them talking and if they show interest in developing a wider understanding then you can guide them towards that. And don't be afraid to say "You know, I don't know, but let's find out" and teach them how to find information, how to check out books from the library, etc. Hell, do that even if you do know the answer sometimes.

Being a kid is kinda like an internship. You want them to understand how to do the basics and get them to the point where they can take out the rubbish without accidentally starting a fire, but a lot of interns lead to great employees, and some even to bosses. But it's not going to happen all at once. Build that foundational knowledge, and let them add to it, guide them as you see fit, but don't pile things on if they're not keen. So discuss Columbus, discuss transatlantic trade, and even slaves, but let them start to connect the pieces and just facilitate their learning instead of just megaphoning knowledge at them. Eventually you could get to a point where a kid wants that, and wants to have in depth, lengthy, difficult conversations about the dark parts of history, but it won't be on day one.

Hope this helps and I've actually answered your question instead of just ranting away.