I don't understand. You're saying that because we've made a lot of stuff, if our civilisation collapses it'll destroy everything? How does one follow from the other?
The emerging global civilization entered some sort of exponential consumption curve a few hundred years ago and the entire planet has been swallowed up in it. The collapse will be of a scale and impact never before seen, because we've never seen anything like this. The usefulness of analogy to previous collapses seems limited to me.
Consider just in absolute terms like the amount mined. We've strip-mined all the easily accessed deposits on the whole planet at this point. If there's a serious technological regression, will our descendants even have the means to access basic resources like lithium? We've extincted all sorts of species on a scale unlike previous civilizations, as well. Unlike every other previous collapsed civilization, there's no going back to the climate-stable and resource rich world of preindustrial humanity to try over again from.
When the Roman Empire collapsed, and the Saxons saw the concrete aqueducts they left behind, they thought that a race of Giants had built them. They'd lost the ability to even comprehend what was involved in building such things any more. It took us about 1000 years to get back to that kind of constructional know-how.
But the Saxons thrived meanwhile. It turns out that you don't actually need concrete aqueducts in order to make babies.
I've wandered around SE Asia a bit. If Civilisation collapsed there's plenty of people there that wouldn't hear about it for a few years, and wouldn't care much even then. Life will go on. People will cope. They'll carry on having babies and growing food.
If we can just somehow make sure the knowledge survives, it might not even matter that much. Our descendants can work out other ways of building stuff, more suitable to the circumstances they find themselves in. Who knows? They may develop better solutions because they never had the easily strip-mined resources.
Japan had very poor iron ores. To make steel weapons they had to develop some incredible methods of forging this poor ore. They ended up producing (arguably) the best swords in the world. Constraints can be overcome and adapted to. We will cope.
We’ve built tool and industrial processes that are bigger that our planet. Look at a cargo ship. Or a mine. It’s mind blowing.
Catch the Trans-Siberian. Or the Indian-Pacific for that matter. Watch as thousands of kilometers of untouched wilderness roll by.
Visit some really poor countries and see the happiest people you've ever met living without technology.
See the ruins of vast ancient temple complexes, remains of entire civilisations that are now just tourist traps.
The world will go on without us.
I can travel to the other side of the world in one day. It’s way too small, or what we built is way too good.
And yes the world as a planet orbiting around a star will go without us. Or at least as a big giant stone.
There is nothing we can do that will kill all life on Earth. We are simply not that powerful.
As a race, we've been through Ice Ages that have seen most of the world covered in ice, and a narrow strip of habitable land around the equator. We survived all that with no technology to help us. Twice. We'll cope.