Feature summary (what you would like to be able to do and where):
SVG, or at least some degree of HTML graphics, should be directly supported in wikitext. For example, Inside of having to use a thumbnail for a pre-made image of an SVG circle, it should be possible to directly insert the circle into wikitext, like so:
This is a circle
<svg aria-labelledby="The following is a black circle">
<circle cx = "50" cy = "25" r="50/>
</svg>
This is consistent with wikitext support for inline HTML and CSS, and would be primarily useful in templates and modules, as will be discussed below.
Use case(s) (list the steps that you performed to discover that problem, and describe the actual underlying problem which you want to solve. Do not describe only a solution):
Many vector graphics, such as https://commons.wikimedia.org/wiki/File:44th_Canadian_Parliament.svg and https://commons.wikimedia.org/wiki/File:Eleventh_Jatiya_Sangsad.svg, would be best off templatized in some form, rather than having to create and upload images from scratch.
The main problem an attempted templatization currently runs into is the fact that it could only output raw SVG, which is not currently supported. As such, in order to create such diagams or maps, one would have to use a text editor or Inkscape to either create a fresh graphic or recolor a previously-uploaded graphic, and upload it fresh to Commons, and then link it from Commons. With a template (and, by extension, inline SVG), one could cut out such a middleman and make the maps directly in the source material, similar to what is already done on enwiki with Template:Graph:Chart.
Benefits (why should this be implemented?):
As largely described above, this would save users much work in having to create raw maps of niche subjects and "polluting" Commons with such maps; it would also, much like Graphs do currently, save users from a thumbnail and allow for direct insertion of graphics into prose.
I am aware the power this gives people might be too great and am fine with reasonable nerfing, perhaps by not allowing other namespaces such as xlink. Also, viewboxes would have to be sorted. I do, however, believe that the benefits greatly outweigh the costs and am slightly surprised that this does not already exist in some form.