How is it that upon telling Google Docs I want to upload an image to be inserted into a document, it will happily open a file dialog that lets me select from a decent variety of image formats including SVG... but only after uploading will it state that the SVG format isn't accepted?

Ignoring the whole "why did it let me select an SVG in the first place" question for now, since that seems likely to be the result of calling by MIME-type and not filemask....

How is it still possible, in this fantastic year of 2019, that web-based application software (especially that of such a web-app juggernaut as Google) can't cope with an image that's a kilobyte-and-a-half of XML that's understood by every browser capable of running the app in the first place?

Okay, sure, I'll just make a PNG of it, but I won't like it.