I often find them a bit of a hassle (you always have to think about Where The Pets Are at any one point) but they're also useful characterisation tools sometimes.

Dante and his cats being a prime point. Back when he was still an unattached ne'er-do-well quietly dealing with his missing memories and his various issues while sleeping around the island, he befriended a feral cat and they would just hang out.

Then after he and Anders got together, one of the first serious things they did together was pick out an adorable, prissy little cat. It wasn't even consciously decided on as a Symbolic Moment, but it kind of is, in retrospect. It fits better with who he is now.