[PeterisP]

Something that's a rounding error on geological time scales is immense in the time scale of technological development.

The development of life took a few billion years to get to where we are now, so if for some otherwise equivalent civilization that highly random process took 0.1% faster or slower, then that makes for multiple million years of difference in development.

If we encounter another civilization, then it would be a wildly implausible coincidence if they happened to be close to us in technological level - say, just a thousand years or so; a more advanced civilization would be much more advanced - and we can see just how much things change in just a few centuries of technological development.