Thanks to Potrace which is embedded into Inkscape since 2008, if not mistaken.
It is used to convert raster images to scalable vector images.
Here's an example: the original jpeg stock image is 580 x 440 px.
Opened in Inkscape and ran Trace bitmap (conversion to svg),
tweaked a few nodes and applied gradients over some parts of the image.
Took about
5 minutes !!! in total and i wasn't even trying hard.
It's pretty good, if you ask me. Would have probably hit 90% similarity if spent some more minutes on it.
The point is - SVGs are scalable vectors, if somebody's not aware, so it can be saved as bitmap image of
practically any sensible size.