I am more willing to bank on climate feedbacks we don't even know about yet doing a number on our ability to keep modern infrastructure running on a wide scale. It depends on regular inputs of resources of no small portion of the periodic table as well as energy sources, and I do not think nuclear/renewables can sustain today's infrastructure.

And of course, there could be nuclear war, societal breakdown as mentioned, another global plague (H5N1? Marburg? Cordyceps? Prions? The possibilities are endless), or, my favorite, Butlerian Jihad. :)