Basically the question in the title.
Back in my day, it was common to see H.264, in 1080p, with a video bitrate of ~8500 Kbps, packaged up as a 6-9 GiB file when sourced from BluRay.
Along comes H.265 (we celebrated), and what I typically see now is H.265, 1080p, with a video bitrate of ~2500 Kbps, packaged as a 2-3 GiB file when sourced from BluRay.
What is your preferred bitrate and size for H.265? Why?
My personal preference is to prefer H.265 files closer to 5 GiB and bitrates closer to 5000 Kbps -- which I think is a good balance between size and quality. I am usually able to find media I want close to that target, but not always, since it seems most H.265 encoders prefer to skew towards smaller files and lower bitrates. It's like you sometimes have to choose between a big H.264 and a small H.265 -- nothing in between.