If our civilization mostly disappeared, then things like large stone buildings, metal and stone statues would survive just the same and all of our disposable junk will have mostly disappeared leaving that skeleton of steel and stone.
I suspect we would even leave quite a bit more than civilizations past considering all of our roads, bridges, dams, and other enormous concrete and steel structures that we have created.
The vast majority of what those who came before us created has been just as transient as what our own society creates. The answer to why most of what we focus on when it comes to archaelogy seems pretty obvious: Survivorship bias.
I am sure - however our own age turns out to end - people will look at some of the monuments we have created in marvel. But luckily, they will not have to look at Twitter or Snapchat.
[1]: https://www.amazon.com/Rise-Fall-Alexandria-Birthplace-Moder...
And you also think after our civilizations is wiped out all the structures we have built would disappear in a matter of few years and no trace would be left after maybe say a 1000 years ?