As an alternative image format to things like PNG? There aren't many, if it's an image that lends itself to a vector format in the first place. SVGs have been widely supported for some time, often have significant file size benefits as we see here, and scale cleanly to different screen resolutions. You have to go back to versions of IE that even the likes of Microsoft and Google won't support any more or to very old mobile devices to start running into general compatibility problems.

One thing to be aware of is that you are effectively programming your graphics if you're using SVG, not just recording the image itself. If you start playing with the more powerful features, particularly using non-trivial filters, you might occasionally run into issues in the rendering code that turns your program into an on-screen image. Depending on how much of that code is in the browser itself and how much is delegated to the underlying OS/graphics drivers for acceleration, that can cause problems including slow display of images, distortion so the rendered image doesn't look right, or in extreme cases even hanging the browser or graphics driver if you're unlucky enough to trigger some underlying bug (which is obviously a rare result, but I have personally seen it happen in my own development work). For the kinds of very simple SVGs we're looking at here, I can't imagine any of these potential problems being a serious risk, though.

Yes, you probably newer encounter them, but they are still there.