It’s because it’s a feature 0 people will complain about adding if it all works well. It’s a small, minor, completely unnecessary detail.

If it’s there, then someone had the time, the energy, and the freedom to add it, just because they wanted to. It’s not an item that will make it on the checklist of a minimum viable game.

If it’s there, it’s a very good sign.

When you see a dog you want to pet it. It’s nice when they place that little extra detail.

Because people like dogs. And like to pet them, even virtually.