h265

I know it was discussed about the CBR vs. VBR Prime Video streams and not sure if this was mentioned. Prime video also has h265 streams, I am not sure if they are better quality but they are smaller. If you are going to give options on stream type why not also offer h265?

So, I have a question. How does transcoding work? When I convert a video file from it's native ISO (video stream VC1 and Audio TrueHD) to H265, how does it work? If the CPU usage isn't at 100% am I loosing quality? If I use my computer for other things and therefore use CPU, am I losing...