The view and the presentational code that builds it are one, they belong to the same presentational layer and always have been. To artificially separate them was a major mistake of the old paradigm. Older approaches, like Knockout, Angular, Vue, etc., have to support presentational code as well, and obviously it is mixed into your html, but in a way that is severely limited and causes complications. Think of it, to be able to do your v-if, v-for, v-else, etc. an entire templating language had to be built, your view isn't part of the scope that that can access the data-model, so dependency injection had to be utilized, components in that model aren't components but directives that have to be registered to re-use one another. The complexity is actually mind-boggling.

These are the exact reasons why React came about - it removes that complexity entirely. It is tiring having to learn frameworks and arbitrary extensions, googling for framework-specific solutions for every trouble that surfaces.