And yeah, you two should probably gang up :)

what is the difference? and why do you write it from scratch?

In fact, npm is not trying to reinvent the wheel. You can find similarities between all three Workspace implementations.

Rather than write new tooling we decided to take advantage of tooling we had in place for our unit tests. Our unit tests already used FactoryBot, a test data generation library, for building up test datasets for a variety of test scenarios. Plus, we had already built up a nice suite of helpers that we coud re-use. By using tools and libraries already a part of the backend technology’s ecosystem we were able to spend less time building additional tooling. We had less code to maintain because of this and more time to work on solving our customer’s pain points.

MJML comes out of the box with a set of standard components to help you build easily your first templates without having to reinvent the wheel.

from my point of view, it is (by far) the best way, to build a layer on top https://github.com/material-components/material-components-web . This is also the path that the Angular Material team has taken, although they have already made a huge effort to create the components themselves.

This is Sass based, and therefore doesn't require Svelte components