I think when they invented the idea back in the 60s/70s that it was a great idea to just use found materials. Land is expensive enough - so if you could just build an awesome house out of crap... then go for it!

But today we have new green building technologies. Like... they used to just use tar and gravel shingles to roof the buildings and that was where water was shed into their drinking water cisterns. Yuck. We know better. Why are they still advocating for using rammed earth tires? We have new green cements that are low psi but they suck CO2 out of the air and they have plenty of thermal mass.

Honestly I want to see the next generation of earthship inspired dwellings. Use modern materials and construction techniques. Maybe one off-shoot will be 3d printed earthships.