But “regular old apps” don’t do all the same things. The whole point of properly developing web apps is that html/css indicates a certain level of semantic und

But “regular old apps” don’t do all the same things. The whole point of properly developing web apps is that html/css indicates a certain level of semantic understanding which allows for different interpretation in different contexts. If you build a web app well, you build it to be a good experience on a computer for a power user with a huge screen and a keyboard for shortcuts, good for a user on a tiny touch screen, good for a blind person who doesn’t use a screen, and good for robots to parse and index. It should even be good for someone on an iPad with a mouse or a pencil which interprets the whole concept of the mouse differently from the desktop user’s mouse. The agreed-upon semantics of HTML and the separation of visual styling into CSS is what allows you to take a step beyond just building an app and add a layer of “say what you mean” such that human and non-human users can re-interpret it into their own devices, use cases, and specific needs. Web frontends are at their best when you don’t expect to perfectly control the end user experience, but try to convey the semantic meaning as perfectly as you can so it can be interpreted into good experiences even in situations where the display is wildly different than originally intended.