Earlier quoted context omitted.
"It's aliens" is just about the least plausible explanation other than "god did it". I'm pretty sure several other sci-fi bullshit explanations are more likely than "aliens are real, have tech we couldn't dream of that relies on our model of reality being totally broken, give enough of a shit about us to visit but not enough to do anything else, and are extremely hard to detect except, for no good reason, in this one…
I'd even argue that "breakaway human civilization living in underground bunkers on Earth" is more plausible than aliens, just because of the vast travel time required to move between star systems within the currently known laws of physics. Both situations - aliens and breakaway civilizations - are incredibly unlikely bordering on impossible. But at least one of them doesn't require breaking any laws of physics.
As for a breakaway civilization, don't you think people would notice resources missing or the insane usage of resources by what would have to be a massive civilization be noticed?
If you take the claims at face value, that these things operate as if inertia does not apply already "breaks physics". And if that is the case ET would make more sense than mole people.
But it is also possible there is nothing to this at all. For me it's ET or a Psyop.