RenderStepped is only really useful if you want something to be in sync with the camera, or are updating the camera. See:
While what you’re looking at is your camera’s direction, we’re not particularly in sync with it. Using a spring means our look angle will lag behind the camera (which is a good thing, as it’s less robotic), so having something completely in sync with the camera is more or less pointless.
RenderStepped also blocks actual rendering unlike Heartbeat which can be done in parallel:
so in general it’s a good idea to avoid RenderStepped unless it’s necessary (which it isn’t here)