But it is kind of verbose, and it’s also a lot slower, so I can understand why the model test might be preferred.

Those frameworks are used in a similar fashion, but conceptually use quite different approaches (Vue is a more traditional one, a library, and Svelte is a "dissapearing framework").

Depending on your needs, you can use the Simple Approach: Wrapping MDC Web Vanilla Components, or the Advanced Approach: Using Foundations and Adapters.

that a better and cleaner approach would be to use computed properties and a validation library that is decoupled for the UI (like hapi/joi).

Svelte chooses a reverse approach.

In contrast, React apps shun templates and require the developer to create their DOM in Javascript, typically aided with JSX.

While Webpack is focused on using CommonJS as its primary module system and converting everything to that, Rollup decided to take the opposite approach — focusing on ES Modules instead.