My understanding of the Share SVG option in OSM is that it fires off a request to https://render.openstreetmap.org, where the mod_tile system uses Mapnik to render an SVG using the Cairo renderer.
It is also well known that the resulting SVG looks great, but is ugly behind the scenes. It duplicates all the style logic, making the file unnecessarily massive,
it doesn’t render text as text, and it doesn’t group anything into layers.
However it seems that Mapnik now has a “native” SVG renderer, separate from Cairo. There are regular commits to that renderer meaning that it’s maintained. Has anyone tried to run it on OSM data, to see what the results are like? I would do so myself, but it would require deploying the whole stack from top to bottom which is a bit daunting.