Comment 6 for bug 170537

> > Since Inkscape already uses potrace, why also use autotrace?
>
> One possible reason: autotrace supports centerline tracing, potrace not.

Feature request for centerline tracing of raster graphics:
Bug #211761 “Centerline tracing”

@Shriramana Sharma: Bug #171414 is about "tracing" vector objects (similar to reverting a 'Stroke to path' operation), which - AFAIU- does not necessarily involve rasterizing the vector object(s) first to then trace the rasterized version again with a centerline option.