we never used a crate!
BUT, we have an xpen (& used this a lot when Avie was a baby!) we still use it for other things(like taking to the park, etc.) Gemma has a play pen that she used since she was a baby!
we also have baby gates!!
so.. i don't think you necessarily have to have a crate.. but some type of pen or confined area is good to have when they are a puppy, potty training, & not trusted in the house when you can not watch them!
if i were you, i would NOT tie up your baby.. God forbid something happen, like getting wrapped up in the leash!!
hope this helps some!