Comment by ndriscoll

Beyond the fact that almost all web "apps" are actually honest documents, let's not forget that operating systems 20 years ago were more "highly interactive, component-based, state-driven, design-system-heavy applications" and still globally (across all applications at once) themeable. So it seems to me that the problem is that modern UI in fact has lost the concept of modular components. e.g. every time someone comes out with light/dark mode as a feature, I can't help but feel like it's an insider joke that's been running so long that the new kids think it's serious. Every single application used to have a more powerful version of that by default. There were GUIs for users that were simple enough to find and use that my 90 year old grandma had customized the theme on her windows 98 machine.