Lets start with this:
The universe is estimated to be approx. 13.8 billion years old (give or take a few weeks)
There are an estimated 200 billion galaxies in the "observable" universe.
If any life exists somewhere out there, it's not unreasonable to imagine that they may be hundreds if not thousands of years more advanced than us.
Just because we exist does not mean that any life out there has to be at the same technological level as us.
Witness the inhabitants of the North Sentinel Island, which has been banned from anyone even stepping foot on the island. They've been there as long as we have in America but still live in huts and hunt with spears........
“Witness the inhabitants of the North Sentinel Island, which has been banned from anyone even stepping foot on the island. They’ve been there as long as we have in America but still live in huts and hunt with spears........”
Exactly right. And compared to these entities we still live in huts and use spears. We cannot try to presume their technology level using our own as an example.
How they construct their craft is interesting. Seamless from elemental atoms they create and assemble themselves. Kind of like 3D printing but making the atoms as needed for each system component. No shaping, soldering, welding, Etc.