My DS is coming up to 2 and will walk the short walk to the shops etc but he still comes with us to walk the dog in the buggy - although I always get him out for part of the walk.
If you are a dog walker how old were your DC before you could take them out to walk without the buggy?
Last weekend we were visiting friends and went for a walk but after a while he didn't want to go in the buggy but he didn't want to walk either so I ended up carrying him.
I can't wait to get rid of the buggy tbh.