How are we Told to explain the ancient technology that has been revealed throughout the planet, much of which can't be replicated or even understood to this day?

What if indigenous humans 'made it' to that point on their own and an outside influence reversed their progress.

What if aliens did not create us but actually conquered us, and then erased and rewrote our planetary history in order to keep the population under control.

Seriously, if technology was a 'gift' from aliens (as has been alleged) what curtailed the progress, literally returning humans to the stone age where we resorted to sticks, stones, and ultimately weapons of mass destruction to defend ourselves against imperialists?

Not exactly a benevolent gift from the overlords…

It's all just a silly theory of course, but one thing is true: Earth is a planet rich with natural and human resources. If there are planetary imperialists (and we know there are) why not expect galactic imperialists attempting to break down Earth's door, too.