Comment by Sesse__

The blur happens on the GPU. HEVC encode also happens on the GPU (or at least a GPU-adjacent device; it's rarely a full-shader affair). If you were to use HEVC software encode with GPU blur, you'd need to send the camera data to the GPU, pull it back to the CPU, and then software encode. Performant GPU readback is often cumbersome enough that developers won't bother.