While I can't comment on romance satisfaction declining fast in non-active households as I've not played rotationally recently, I am still experiencing a rapid decline in the romance bar and romantic satisfaction. (If this needs to be moved to a separate thread please let me know; I'm adding it here because the previous report covered both.)
I started a new vanilla, mod and cc free, save after the 1.116.202/2.14 patch and have a couple living together in a romantic partnership. I get them to 'Very Satisfied', which should mean their bar drops slowly, however if I play a sim day without any romantic interaction between them the romance bar has dropped about 20% by the end of that day, sometimes to the point where they are no longer very satisfied.
I played with sim couples in other older saves before the 1.116.202/2.14 patch and in my opinion the drop in romantic satisfaction for sims who are 'very satisfied' in their relationship and their romance bar post-patch is at the same rate as before the patch, so it doesn't feel like it has been fixed at all to me. Neither sim in this new save has the 'fear of being alone' fear (the sims I played with in older saves who lost romance and romantic satisfaction very quickly also didn't btw - it's one of the few fears I haven't experienced in my game yet!).
Happy to share my save file if it would help.
