Not the OP, but my partner and his wife have done this for years.

I was inspired, and I did a variation of it with a partner at one point. It was really nice. Feels kinda like a synthetic version of an engaging conversation with someone you care about, but perhaps with words you can't muster yourselves at that time of the day. If you've chosen the book together, it's guaranteed to be the right thing between you. It's nice to feel like you're hearing or learning something interesting from the person you care about, even when one of you perhaps don't have the conversation or the story in you. (I have a high appetite for connecting over ideas, but sometimes people I care about can run out of capacity before me, so it feels like a hack for my relationships.)

I imagine swapping reader-listener roles is another variation.