I agree that demos like this are a wonder of "real skill". But it's bizarre to assert it's the only place it's possible. Yes, most software development is boring business stuff built on unstable towers of boring frameworks and infrastructure.

But there's plenty of room for art in your code. Either straight out art like this; generative computer art is a very exciting aesthetic area. Or just building elegant systems. There's no reason a network caching layer or a machine learning library can't be beautiful and skillful the same way a demo is. (The one exception is terseness; the tricks necessary to shoehorn a beautiful demo into 4k often make code unmaintainable.)

Aesthetics matter.