SVG is great for vector graphics, but you still need pixels for photos (and thus need to decide on 1x, 2x, 3x). Once everyone has 2x devices and we don't bother creating 1x anymore, what will be the point in designing at 1x? I'm suggesting (what I consider) a more modern workflow that's looking past 1x. Its days are numbered. Mobile and tablet are already all 2x. We're still waiting for desktops to complete the move to 2x (although that will likely take years). Photoshop is not a great tool for SVG design (which is why I do prefer Sketch, and maybe some day Adobe XD), but for now some people are stuck using Photoshop and they have to make the best of it. When using Photoshop they'd typically use Illustrator to export most of the SVGs.