Would you consider the Stripe[0] dashboard or Figma[1] ugly? I'm not agreeing with the parent's statement, but whether or not a WebApp or Native App is ugly is impacted more by designers, not implementation.
Good point about complex images. I do not think this issue will be solved anytime soon. An individual's mental image of a complex idea like inheritance or a data structure is subjective. Tying a specific visual GUI to a complex model (that many users would agree upon) is a very difficult design problem. Text allows the user to interpret the model using their own imagery.
[0]: https://stripe.com [1]: https://www.figma.com