My hubs and I watch very different things. Him: photography equipment reviews, photography how to’s, and old, OLD movies. Me: Pathfinder 2e, quantum field theory/mechanics and Dip Your Car.
Yet we both see stuff in the other’s Suggestions of videos the other recently watched. There’s ZERO chance based on my watch history that without IP-based suggestions YT is going to think I’m interested in watching a Hasselblad DX2 unboxing. Same with him getting PBS Space Time’s suggestions.