Listening to these far away stars for electronic signatures would be like going back in our history to 1M years ago a making the conjecture that there is no life here.
We are looking at data points that are millions of years old by the earlies count. So not really relevant to what may be out there today. Maybe life started there at the same time that it did here. They will discover us millions of years from now.
Maybe the only stars we see in the sky that are still there are about 10000 years old. The rest flamed out long ago..( we see their light) but they are gone.