No bones or other remains of any civilisation have been found in the soil.

I don't know why you think aliens came here to build something for humans or help them with something. They might just have built some stuff for themselves that they used for a while, then left (or no, they're still here, they just don't show up to us because they don't like us, lol 😂)
All kidding aside, but I'm not ruling out any theory. Yes, bombastic headlines are misleading and almost always conceal an attempt at manipulation or deception. To begin with, I set aside all categorizations in the style of "the most" of something - the oldest, the largest one, the first in the world, etc.
But think of something else. I always give as an example our history from the recent past - almost at the end of the last century. Not even 50 years have passed since then and historians in Bulgaria still fight and argue among themselves about what happened in certain years. Much of the documentation has been destroyed.
Well, my point is this: imagine if we have no real track and certainty of what happened just 50 years ago, then how do we know what happened 27,000 years ago? 🤔 Aren't these just speculations, attempts to attract attention or serve someone's interests? They can't convince me it's anything different.
Still, it's interesting to read. Like I said, I'm not ruling out any theory. 😃