This is why learning is fun. You're doing the work of the finest humans. Love to see this and damnit, I want to know more to participate. I think it's working...
I realize you're joking, but...
Not the soil itself but them burrowing. The old ones eventually backfill with topsoil, and that helps make the topsoil thicker and less dense in a way, over time as multiple burrows are created. This is part of the reason why gophers are a keystone species on the prairies.