Fun subject, thanks for posting!
Part of the issue to me is that there is such a large distance involved in the universe that everything we are observing is many, many years back in time. If you were to look at a civilization like we have even 300 years ago there wouldn't be any easy way of detecting it from the nearest star. Additionally, imagining the progress we make in say a thousand years, (should we decide to play nicely) it would be conceivable that we could develop technologies for communication and energy manipulation that would be undetectable to our present level of technology.
Such technologies could harmonize so well with the planets ecosystem that no detectable energy signatures or radio signals are emitted. Observing such a civilization from a distance without a clue of what we are seeing could lead us to believe no life lived there. (By the same logic, if you see a planet with occasional strange bursts of lights, odd looking industrial discharges in the atmosphere and em emissions – this might be a clue to stay away for a while and avoid landing there) ;)
For example, a simple invention like a really good night vision glasses or genetic modifications for night vision could eliminate the need for artificial lighting and would free up a lot of energy needs and avoid light pollution. Observing such an advanced civilization from a distance wouldn’t resemble ours at night. A lot of what makes us visible is that our technology hasn’t advanced to the point where it has become fully efficient imho.