1080P HD is acceptable for most content, sure 4k HDR looks much better, but given most of the streaming services have a mix of 4k and "HD" material, I wouldn't hang them out on that alone (but agree that it should be an included option).
Sound is the big one for me, no 5.1 is simply a disgrace. There is no excuse for this and for me this demonstrates Sky's sheer arrogance of its market position, that it doesn't strive to deliver best product they can for the market simply what is they deem is okay. I asked on their facebook and via email a few years ago if 5.1 was coming and "it was on their radar". Just shows that unless they are motivated by a decline in revenue / profit AND that decline can be attributed to their piss poor products, the won't do anything about it.

