especially true if you consider that if there were hundreds of civilisations scattered across the Universe, the average distances across space and time would still be hundreds of times larger than we could deal with right now, or perhaps ever

for a civilisation with advanced rocketry and telescopes similar to what we have right now, it would still be very unlikely to observe us - firstly because we've only been around at all of a tiny fraction of the time the planet exists, and secondly because despite of all the ruckus we are currently causing in the planet, we'd still be very hard to observe from sufficiently far away