I don't agree with you that it's pointless. Since it's canon and it's to be considered 699.5, I'm looking forward to it. Kaguya as a villain never made much sense to me, maybe this will let us know what her true purpose was and why she needed an army. It's possible she didn't agree with what Toneri was planning and wanted the chakra and an army to stop him. Also we might find out more about Hamura. We will find out more about Kaguya's background,since Toneri wants to create another Kaguya through marrying Hinata and having children with her.
I'm looking forward to learning more about the Hyuga Clan's origins. It was hinted at by Kakashi a long time ago that all dojustu derived from the byakugan, which means the Hyuga Clan might have come from Kaguya's planet or dimension. At least one of of Kaguya's parents must have been a Hyuga. To me the romance is secondary. You also need to consider there could be a translation problem. Kishi could just be emphasizing the romance aspect due to complaints from Japanese fans. Romance is a part of growing up and maturing, so he could be including it for that purpose only, as well as tying up loose ends.
So whether to watch or not is up to you. I don't think anyone would hate you for it.