I'm asking you as a doctor: is it normal to replace a husband with a chicken, and not to miss anything about the husband, not even for half a minute?
This is advertised as a "story of undying love, loss, and resilience" but I would characterize it as a story of selfishness, cowardice, and stupidity. It's a little mortifying to consider the possibility that more than a tiny fraction of people in the real world might resemble the protagonists. Personally, the only character I found likable was the chicken. (I'm delighted to report that the chicken gets a happy ending.)
That said, the increasingly-salacious conversation between two cranky elderly people that constitutes the bulk of the book is completely absorbing, in much the same way that I imagine soap operas are.
Loriano and Nives have an affair and make plans to elope without warning their spouses. Nives tries to follow through, but Loriano either gets cold feet or was never sincere to begin with. Bizarrely, the book seems to want us to judge Nives to be entirely the victim and Loriano to be pure scum; even Loriano's wife, Donatella, instantly sympathizes with Nives when the affair is revealed. But both of them revealed their reckless disregard for others by having the affair in the first place. And both of them reaffirmed that disregard by their subsequent actions: Nives was ready to ghost her husband (there's no indication that he had wronged her), while Loriano just wanted to keep it all a secret and escape consequences. I think any morally sound handling of this situation would begin with each of them confessing the affair and being honest with their spouses about their intentions, whatever those intentions may be.
At the end of their phone call, Nives has developed such a low opinion of Loriano (and a high opinion of Anteo by contrast) that she reinterprets her entire life, now pleased with how things went: "Six lives wouldn't be long enough to leaf through the golden album that has suddenly opened inside me." This strikes me as a paltry substitute for an actually happy life. Can a few years of belated gratefulness really make up for decades of bitter resentment?