It’s all about affordances! And tradeoffs! HTML doesn’t have a native way for us to make “tabs”, but maybe it will someday. The road to get there is long and requires a ton of researching, prototyping, spec writing, and god knows what all. Dave has been on that road for a while now with the gang at Open UI and they are honing in on a prototype that allows for “tabs” to do what tabs do best (hide and show content) with very simple semantic HTML.