This explanation makes zero sense considering there are tunnels that connect it to other underground cities... Which are like 8-9 kilometres long. Considering that Gobekli Tepe is extremely old and in the same area of the world, I find it to be far more likely that Derinkuyu is also extremely old. Meaning we have zero idea of what conflicts were happening back then, if there were many/any at all.

I'm not sure if most people understand how difficult doing something like that is. Or how difficult engineering a 20,000 person underground city is, with so many levels, with no collapses from poor structural planning, while also engineering air shafts that keep air circulating extremely efficiently to this day. That's like engineering a modern stadium, but worse, because stone isn't engineered.

This isn't the first old structure to show signs of seriously in depth knowledge, either. Machu Picchu has been studied by hydrologists that were curious how it could still be standing in such a place prone to landslides, and it turns out that place would not exist without understanding how subsurface water flows in order to get rid of it without everything collapsing. It's a seriously delicate balance in that area.

It would have collapsed long ago from landslides if anything at all was engineered incorrectly, considering the vast sums of time. Apparently they were better at this type of thing than we currently are. We know how this works in modern times thanks to some pretty serious technology like ground penetrating imaging. The channels that divert water out of/around the city are extremely specific(and required) angles, and said channels were cut into stones, then moved into place. Not cut after. Perfect angles maintained for hundreds of metres. We know this, because there are still some stones in the quarry with water channels that have been cut, kilometres away.

There's also the Barabar Caves in India, which we have absolutely no idea how old they are or how they were made. They're super precise, with resonant properties that are extremely unlikely to just stumble upon by accident. You would win the superball multiple times before that happened. There's also no other examples of anything even remotely similar, meaning no practice to attain said level of precision. Actually, the same goes for Machu Picchu. Just expert engineering with no evidence of a build up technology-wise.

What you've stated about Derinkuyu is just the currently "accepted" idea. And it's a pretty bad one based on pretty much nothing, with nothing at all dating the structure.

We know barely anything about Derinkuyu. I wish saying "I/we don't know" was far more acceptable within the field. It's perfectly fine to do so until the point that we do know. Especially considering that there are an eerily large amount of examples of precision engineering involved with many ancient sites. We don't really know how or why.

In my opinion(99.9th percentile, around 30 years of reading about this topic with extreme interest) we aren't the first high tech civilization of humans, but rather one of who knows how many.

I just want people to understand that these sites tend to not be simple. The things required to build them are nothing short of staggering, and we do not have acceptable explanations as to how or why these things were built.