Feature summary (what you would like to be able to do and where): SVG files should embedded in output HTML and be rendered client side, this will enable a number of things that the PNG served files prevent. In particular, it will make it so SVG images can automatically adjust depending on the browsing users' light/dark preference.
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): Dark mode on Wikipedia currently operates independently of the system-wide setting and doesn't seem to use prefers-color-scheme to detect what mode the user is currently using. If there is a mismatch between the dark mode as currently implemented, and an SVG image is served directly detects the opposite, this can lead to invisible or hard to see images.
Benefits (why should this be implemented?): Makes the entire site work with images that are compatible with prefers-color-scheme, and encourages editors/creators to upload images that utilize this technique to make images dynamically adjust to the system/browser in real-time. Improves readability for users who utilize dark mode, which is also an accessibility concern.
For some example images that utilize prefers-color-scheme see https://en.wikipedia.org/wiki/Category:SVG_images_that_support_dynamic_color_schemes
See also T5593: [Epic] SVG client side rendering T26070: [GOAL] Provide a dark / night mode skin or theme and the Community-Wishlist-Survey-2023 items Dark mode and Native SVG support