I don't disagree with anything you've written there, but I still disagree that UI code is typically or inherently more complex (or harder to write well) than ba

I don't disagree with anything you've written there, but I still disagree that UI code is typically or inherently more complex (or harder to write well) than backend code. I doubt it's anything you can even prove one way or another. But while the nature of inputs and outputs for UI code tends to be nebulous and somewhat poorly defined, it's hard to argue the range of possible inputs compares with code that has to process massive datasets.