"Stylus to SASS" refers to the process of converting styles written in Stylus into the original SASS syntax (also known as the indented syntax of Sass).
SASS (not SCSS) uses indentation instead of curly braces and semicolons, similar to Stylus, but has its own rules and syntax. Stylus and SASS both compile to CSS but have different syntactic structures and feature sets.
You may want to switch from Stylus to SASS for the following reasons:
Better support and community: Sass (including the indented syntax) is widely supported and has more learning resources.
Consistency in the toolchain: If the rest of the project or team uses Sass, switching avoids inconsistency.
Framework compatibility: Some frameworks and tools rely on Sass rather than Stylus.
Stylus is less commonly used and not actively evolving, whereas Sass continues to receive updates.
When your project or team is standardizing on Sass (especially indented syntax).
When you want to simplify your CSS without curly braces and semicolons, but with more structure than Stylus.
When integrating with tools or frameworks built around Sass.
When Stylus’s unique syntax causes confusion or lacks support in modern build tools.