Scott Turner, who has an entire blog “Exploring procedural generation and display of fantasy maps”, gets into why vector graphics seems on these surface why it would be bad for the look of a pencil stroke:
Something like this pencil stroke would require many tens of thousands of different elements. Basically each little blob of gray in that image would be separately defined.
But, SVG filters to the rescue.
It’s all about <feTurbulence>. Squigglevision! We’ve covered SVG filters quite a bit.