> Yes, some applications tend to have a large amount of markup for what seems like simple features (the Slack’s input box example). However, the alternative is that browser vendors bake it all in, and then every app is stuck with the opinionated way they think is right. Perhaps some amount of chaos is healthy.

Or, you know, provide a set of usable controls that provide useful functionality out of the box and provide a set of useful APIs so that people can either extend those controls or create their own.

Web Platform provides neither. Compare that to literally every other UI toolkit under the sun. Turbo Vision from 1990s was a better toolkit than anything the web has to offer.