If you’re sharing the account the main account holder most likely cares about resolution etc. than those sharing off them. I’d cater a guess that they’ll watch whatever resolution is on in front of them. My mate watches HOTD on his iPad via Now TV which caps their resolution at 720p at a low bitrate. It’s grainy to my eyes but most people wouldn’t care. I do. A lot of people watch at that resolution and do not care about it being higher. If you showed them side by side comparisons between 720p and 1080p, people would notice but not care enough to pay for it. However, 1080p and 4k streams are negligible, Hell, even I can’t tell the difference at times between high bitrate 1080p copy vs high bitrate 4k copy. The only reason I pay or look for better versions is because I know it’s out there and I’d like even the most incremental upgrade to my media. However, most consumers are not like this and are happy to watch at 720p if it’s passable quality and if it’s convenient (price and accessibility).