Robert Maxwell wrote:
I don't think humans are 100% extinction-proof, however, I do think we could survive a lot of things that most other species could not. Besides, there are billions of us. Even if you whittle that down to a few thousand, that is a survivable number of people to prevent extinction.
For most extinction scenarios, we've become nearly invincible for the moment being. But one has actually increased substantially with the ease and abundance of travel – a global pandemic. A devastating one is more likely than ever, and it can cripple our civilization to a point where we are vulnerable. It can become difficult to sustain it as it is now, and we can revert by necessity to a more simple way of life where survival is less likely.
Now, you can be optimistic that the memory of the great past, including the surviving physical records and artefacts to support it, will inspire the fallen civilization to rebuild and restore everything, even if it takes many generation to do so. So it should take much much much less time than what it took us to get where we are now (which was not that much to begin with). But you never know...