I had discussed it with my wife. I didn’t want her to feel obligated to do so, and I know it would be awkward at her work to change her last name, but ultimately she wanted to - so I guess that’s one reason?

There is a degree of closeness from it that I think some people appreciate. If you all share a last name, perhaps you feel closer as a family? I’ve known some people that don’t share the same last name as their kids, or people that went double-barrelled, but didn’t with their kids, and some of them had either changed later, or regretted not having the “same” name.