Piracy: ꜱᴀɪʟ ᴛʜᴇ ʜɪɢʜ ꜱᴇᴀꜱ

It's not odd at all. It's well known this is actually the truth. Ask any video editor in the professional field. You can search the Internet yourself. Better yet, do a test run with ffmpeg, the software that does encoding and decoding. It's available to download by anyone as it's open source.

Hardware accelerated processing is faster because it takes shortcuts. It's handled by the dedicated hardware found in GPUs. By default, there are parameters out of your control that you cannot change allowing hardware accelerated video to be faster. These are defined at the firmware level of the GPU. This comes at the cost of quality and file size (larger) for faster processing and less power consumption. If quality is your concern, you never use a GPU. No matter which one you use (AMD AMF, Intel QSV or Nvidia NVENC/DEC/CUDA), you're going to end up with a video that appears more blocky or grainy at the same bitrate. These are called "artifacts" and make videos look bad.

Software processing uses the CPU entirely. You have granular control over the entire process. There are preset parameters programmed if you don't define them, but every single one of them can be overridden. Because it's inherently limited by the power of your CPU, it's slower and consumes more power.

I can go a lot more in depth but I'm choosing to stop here because this can comment can get absurdly long.