You’re right, SATA isn’t going anywhere for a very long time. If you have a need for 4+ TB of total storage there is nothing at all wrong using HDDs or 2.5" SSDs.

You’re completely right. The framing, which is what this 3D printing replaces, is one of the fastest parts of home construction.

The site preparation, utilities, and interior finishing work are what take the longest. Modular homes can significantly speed up all of those components.