Not sure I'm offering anything new here - just my personal perspective...
I'm one of the many that has LightBox free as part of my Spark unlimited broadband package. I actually quite like it and have watched a lot of stuff I've really enjoyed - mainly UK and Scandinavian TV shows. I also pay separately for Netflix, Spark Sport and Sky TV. I've been planning to drop Sky for a while and will do that soon, as I'm paying a fortune for it and not getting my money's worth. I used to watch a lot of sport (and will miss Champions League football), but I just don't have enough time any more. I often record shows in my planner then delete them because I don't get around to watching them.
I'd be happy to pay for "NeonBox", provided: the content included existing LightBox and NEON content (don't drop that UK and Scandi stuff that's not on Sky); the platform was good (TBH I'd be happy if they just added NEON content to the existing LightBox platform); and the price was reasonable (say, comparable with Netflix, give or take a few dollars). Presuming you wouldn't have to be a Sky subscriber (like you don't have to be now for NEON) this would make cancelling my Sky subscription a no-brainer.
So there's the problem for Sky. Why offer me a (say) $20/month service so I can cancel my $104/month service?