See Choosing an image format. For JPG, PNG, SVG, WebP, I believe they all work much the same once a texture is created, so you’re basically optimizing for download speed. SVGs are rasterized, so they render as pixels, not vectors. Compressed textures are optimized for GPUs.
For actual rendering, the most important thing is using multiframe textures (atlases, spritesheets) and arranging the display list so texture swaps are minimized.