Maybe one of the few upsides of this tech is the customizability. Sure, you can get a prefab house built in a week or less if you try, but it's going to be constrained by the prefab shape and layout, even with modular blocks there are still design constraints, like with https://www.wikihouse.cc.

As seen in other environments, 3D printing lets anyone design and build for their own use case. People are not all about practicality, they want to like their environment too and being able to bring up your house exactly the way you like it is great.