4) There is a very easy and unavoidable way to destroy the universe (or make it inhospitable) using technology, and any technological civilization will inevitably do so at a certain pretty early point in its history. Therefore, only one technological civilization per universe ever exists, and we should not be surprised to find ourselves to be the first.
5) The Dark Lords of the Matrix are only interested in running one civilization in our particular sim.
Re 4), is this destruction supposed to violate relativity? Also, if so, why do we find ourselves so late in cosmic history? Similar anthropic considerations interfere with a non-FTL destruction mechanism like vacuumn collapse.
We have a sample of one modern human civilization, but there are some hints on how likely it was to happen.
Major types of hints are:
Data for:
Data against:
To me it looks like life, animals with nervous systems, Upper Paleolithic-style Homo, language, and behavioral modernity were all extremely unlikely events (notice how far ago they are - vaguely ~3.5bln, ~600mln, ~3mln, ~200k or ~600k, ~50k years ago) - except perhaps language and behavioral modernity might have been linked with each other, if language was relatively late (Homo sapiens only) and behavioral modernity more gradual (and its apparent suddenness is an artifact). Once we have behavioral modernity, modern civilization seems almost inevitable. Your interpretation might vary of course, but at least now you have a lot of data to argue for your position, in convenient format.