Astronomy

We don't want to be near the galactic center, there's too much radiation. A quiet spot out on one of the arms away from supernovae and active objects is a much better place for life to evolve.

At this point our own radio is even too advanced for an alien civilization to detect. An interesting thing about radio is that aside from a few lingering powerful analog signals (AM/FM radio, active radar) our modern spread-spectrum radio is hard to distinguish from background noise. It's an interesting consequence of information theory, as bandwidth and noise tolerance grow, if you aren't looking for a signal it becomes almost invisible. We also do a lot with very little power now due to these amazing encoding methods, when I was a kid and the analog cell phone was novel we would have outright said that a phone could never communicate directly with satellites. Not enough power or antenna in your pocket. Yet here we are.

So any civilization that develops radio is only likely to send out a short burst of detectable radio before disappearing within 100 years, even without switching to an alternate technology. This makes radio an almost impossible thing to search for in a vast galaxy where time can separate us even more than space.