Nice discussion in comments but, you have missed one thing, look at the number of users:
![enter image description here](https://cdn.statically.io/img/i.sstatic.net/defhi.png)
Now, it is easy to understand, that this node setup only builds one spiral. Moreover, look at spiral node, it has some inputs that we can spot in the screenshot:
![enter image description here](https://cdn.statically.io/img/i.sstatic.net/YowpO.png)
Knowing that, it is easy to understand that this node group builds one spiral, and then you just duplicate and modify inputs and scale plenty of times manually to create this quilling pattern.
Here is how one spiral may build, I used spiral node and add scaling to them with logarithmic progression to make it more "unfold". Looks like divergence value is doing this in the original setup.
![enter image description here](https://cdn.statically.io/img/i.sstatic.net/9K1uC.png)
Now we can add depth, but before doing that I want to make them equal height and thickness, without matter if they scaled or not. So here is why global reference is used. Just set plug the relative scale into Set curve radius.
![enter image description here](https://cdn.statically.io/img/i.sstatic.net/f2NeV.png)
Final touch is trim curve by common value, you can see the animated value here:
![enter image description here](https://cdn.statically.io/img/i.sstatic.net/UIHXA.png)
I have added weighted normals modifier and you can animate growing sheets:
![enter image description here](https://cdn.statically.io/img/i.sstatic.net/AwbUu.png)
You can also output a position of the points, to use it in shader to make this gradient look:
![enter image description here](https://cdn.statically.io/img/i.sstatic.net/PptPe.png)
I'm not quite sure about how to unfold spiral to make it almost linear at the beginning, maybe he has used another method, but overall setup looks clear for me.