UPD: to those wandering here for any workable solution:
i discovered this: there is a plugin that allows for saving canvas into html, so
- install the HTML Export plugin: Plugins - Obsidian
- export your canvas as HTML
- open it in your browser and save the page as a PDF by right clicking it
- open it in Adobe Illustrator and export as SVG
with this gruesome process i was able to get somewhat satisfiable SVG file. but still, it turned out to be 800kb (which is a lot for a vector file) and the fonts looked quite ugly. Still better then the PNG, if you ask me