When Simple Charts Fail (And When Complexity Is Worth It）

We say “keep charts simple” like it’s always right.

It isn’t.

Simplicity is one of the most common principles in data visualisation. We repeat it often, and for good reason. Simple charts are easier to read, faster to understand, and less likely to confuse.

In most situations, simplicity works.

But somewhere along the way, a guideline became a rule. And when that happens, we stop thinking.

Because simplicity is not the goal. Clarity is.

The Comfort of Simplicity

There’s a reason we lean so heavily on simple charts.

They reduce effort.They speed up understanding.They help audiences feel confident in what they’re seeing.

In data storytelling, that matters. When something is easy to grasp, it builds trust quickly.

So we default to simplicity. We teach it. We encourage it. We design for it.

And most of the time, that’s exactly the right call.

But not always.

When Simplicity Starts to Hide the Truth

A chart can be clean, elegant, and completely misleading.

Not because it is wrong, but because it is incomplete.

Important relationships get flattened. Subtle patterns disappear. The nuance that actually matters gets stripped away.

What remains is something that looks clear, but says very little.

And that’s the danger of oversimplifying. You don’t just remove clutter. Sometimes, you remove meaning.

A Better Question to Ask

So instead of asking:

“Is this chart simple enough?”

A better question is:

👉 “Is it worth the effort to understand?”

Every chart asks something from its audience.

Time. Attention. Mental effort.

Even simple visuals require a bit of thinking. As complexity increases, so does that demand.

And if we ask for more effort, we need to give something back.

A deeper insight. A clearer connection. Something that wouldn’t have been visible otherwise.

When Effort Pays Off

Brent Dykes describes this idea as the epiphany payoff, the moment when the extra effort suddenly makes sense because the insight becomes clear.

I think of it more simply: If a chart takes more effort, it must give something back.

Source: Brent Dykes, Epiphany Payoff Framework (effectivedatastorytelling.com)

The framework highlights a simple trade-off.

Some charts are easy to understand but offer little value. Others require more effort, but when done well, deliver deeper insight.

The goal is not to avoid complexity. It is to make sure that when we use it, it earns its place.

When Complexity Reveals What Simplicity Cannot

A classic example is Minard’s visualisation of Napoleon’s march to Russia.

At first glance, it feels dense. It combines geography, direction, troop size, and temperature into a single visual. It is not designed for instant understanding.

But spend a moment with it, and something shifts.

You don’t just see movement. You see loss.

You begin to understand how distance, time, and brutal weather combined to destroy an army. The shrinking line is no longer just a design choice, it becomes a representation of human cost.

This is not a chart that is easy.

But without that complexity, the story would disappear.

When Complexity Shows the System, Not Just the Numbers

The same principle applies in business.

Take flow-based charts such as Sankey diagrams.

At first glance, they can feel overwhelming. Multiple paths intersect, split, and merge. There is no single linear story.

But that is exactly the point.

These charts reveal how people move. Where they drop off. How decisions evolve across stages.

A bar chart can tell you how many.

A Sankey diagram shows you how.

And in many real decisions, the path matters more than the total.

When Complexity Becomes Noise

Of course, not all complex charts earn their place.

Many look sophisticated but offer very little in return.

They demand attention. They slow the reader down. But they don’t reveal anything meaningful.

Most complex charts don’t fail because they are complex.

They fail because they have nothing to say.

And when effort leads to nothing, the audience disengages.

Guidelines Are Not Rules

This is why guidelines like “keep charts simple” exist.

They protect us from unnecessary complication. They give us a strong starting point.

But they are not rules.

They are defaults.

And good data storytellers know when to move beyond them.

They know when to simplify, and when simplification goes too far.They know when complexity clarifies, and when it confuses.

Final Thought

Most of the time, simple charts are enough.

But occasionally, a more complex visual reveals something deeper, something a simpler chart would miss.

The question is not whether a chart is complex.

It’s whether the insight is worth the effort.

Because effort is a cost.

And insight should always be the return.

Credit: This article draws on the concept of the epiphany payoff by Brent Dykes, which explores when complex charts are worth the cognitive effort.