The headline replicates a quote from one of the on-air personalities delivering coverage of Relativity’s 3D Printed rocket Terran 1. You can watch that launch in the video.
One of the things that 3D printing of the structural components of a rocket offers is a reduction in the number of seals required between mated components. Fuel pathways, for example, can be printed right into the body of a component instead of requiring piping and seals.
When perfected (the Terran 1 launched successfully but its 2nd stage apparently suffered an anomoly and the craft failed to reach orbit), this technology can potentially make rockets both easier to make and more reliable.
Check out the video below: