Exactly this. There may not be a 'standard' that does any of this already, but the goal of this being portable across websites requires all of those websites t

Exactly this. There may not be a 'standard' that does any of this already, but the goal of this being portable across websites requires all of those websites to support this 'new' standard -- so there probably isn't a way this becomes wide spread enough to be useful. Relatedly, this follows the Notion model, where the UI is intrinsically tied to and limited by the data model. This may have appeal to developers who already are primed to think that way, but it's a terrible UI paradigm for everyone else.