perfectly reasonable quality 4k 10-bit hdr x265 is around 1gb/hr - the files I see that are 10-20x larger webrips from streaming networks seem to mostly contain noise and all compress back down to ~1gb/hr after denoising

You might want to check your math again. 1 GB/h is 2.3 mbit/s, if we're being generous. That would be absolutely riddled with compression artifacts unless you're encoding a screensaver.

2 Mb/s is awful for anything with movement, 8 Mb/s is decent enough, 20 Mb/s is very good to my eyes, and 80 Mb/s is nice, clearly better especially in scenes with significant movement, but it's not revolutionary. I don't watch webrips unless there's no other option, it's mostly WEB-DL or bluray rips.