I do personally for color control. You can see my heavy use of SVGs here at a site I'm in the middle of implementing [0]. For example, if you look in the :root {} you will see a lot of CSS variables that are declared and which manipulate their HSL value based on base variables like --hue. The SVGs implement these. So you can change the global --hue, and the hue of all the SVG elements on the page will change. I've modified output SVGs from figma/illustrator to reference a variable rather than a hardcoded fill i.e. <path fill="red"> becomes <path fill="var(--base)"> That's a simple example, you can go further to change relative saturation and lightness as well, which I also do with CSS calc(). It's fun!

[0] www.holysnacks.us