They don't need to be two flights but they take up half the footprint that way making them much easier to fit into a design. An escalator can't make such turns so they need to be straight, making them a bit awkward to plan around.

This actually makes a lot of sense hahah thank you!

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In case of emergency. Depending on where you live there is usually building code. Steps that are 8in high are standard for fire escape routes. Instead of making the stairs twice as steep, they create a turn.

> An escalator can't make such turns so they need to be straight,

Side note, curved escalators can be made, but they're very expensive (I've never seen one outside of Las Vegas) and take up a huge amount of floor space in comparison

You could do the same thing with an escalator by having a landing in the middle, and this does happen at times.

Technically that is two escalators which increases the cost.

Yep.

(Of course two flights of stairs are also two flights of stairs. But yeah, the cost thing.)

It also seems like having two flights is safer if someone falls from the top step.

Two flights of 10 steps are not significantly more expensive than one flight of 20 - all you're adding is the landing. Two escalators means twice the mechanical equipment.

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Not correct. If you look at how escalators work (eg 3D animations), the step height is a variable that can be completely varied through the length of the escalator. So it can start flat, go up a flight, go flat again, go up again etc very easily and still be the same escalator. It works so simply it is amazing.