There was a 10+ year old bug thread with 100s of +1s for SVG support in Docs. IIRC the reasoning behind the delay was security concerns - seemed like a bit of a cop out, but what do I know?
Download Inkscape and then convert your SVG to EMF (some PowerPoint vector format I think).
/Applications/Inkscape.app/Contents/MacOS/inkscape file.svg --export-filename=file.emf
Upload the EMF file to Google Drive with content type “application/x-msmetafile”.
rclone copyto --http-headers '"Content-Type","application/x-msmetafile"' file.emf gdrive:file.emf
Right-click on the file in Drive and open in Google Drawings (if Google Drawings isn’t an option, you don’t have the right content-type set on the file.
Copy from Google Drawings to Google Slides.
Enjoy your painful-but-at-least-possible vector objects in Google Slides!
This is the second time that the EMF file format has come in handy for me. In college I used to export my Matlab plots as EMF so they'd import into my Word documents all crisp - it was the only format which enabled that (please don't tell the LaTeX folks I did my lab reports in Word).
I'm also excited by what you can potentially do programmatically in Figma. Has anyone ever tried using the google slides API? It’s one of those APIs where you sort of wonder if you are the only actual user or if other people just enjoy eating razors to feel alive.
Footnote rant: And WHY Google for the love of all things can you STILL not import an SVG into a google slide deck?! It's supposed to be web software for crying out loud!