I'm not an expert, but didn't it take quite some time for stars to create heavier elements like iron, go nova, spread the star-stuff across the Universe, and th

I'm not an expert, but didn't it take quite some time for stars to create heavier elements like iron, go nova, spread the star-stuff across the Universe, and then repeat until we have the current mix of light/heavy elements? Combine that with: * The fact that life on Earth was possibly dependent on life from other planets to form. * Has had multiple near-total extinction events during it's time. * We're outright dependant on fossil fuels left over from previous cycles in order to get to where we are now. * Our own species have been close to extinction multiple times far before we reached our current technological level. * Our own emissions most likely blends with the background noise and are probably not detectable that far out. * It's taken us countless millennia just to get to the point where we're approaching a technology level that will allow a fraction of our population to scan parts of our closest galactic neighbourhood for disproportionately large signal sources that happens to be on the bands we find to be most convenient. To me, it sounds like it's quite plausible that we could be amongst the first to spread on an interplanetary scale (assuming we actually manage to do that), or that something happens and we go back to pre-industrial levels, leaving the aliens on the next habitable planet wondering why the level of noise from group of stars a few hundred light-years away suddenly grew quieter.