Seems to me that we should be able to detect signs of biology from the atmospheres, even of exoplanets. High nitrogen and CO2 traces in spectra would appear a tipoff.
CO2 and N2 are inert gases that could appear anywhere; free oxygen in the atmosphere is what you’re really looking for. Oxygen can’t exist long term without being continuously replenished via photosynthesis.
There are numerous Class M planets in the galaxy. Most have humanoid life. Most speak English. We just have to develop warp drive so we can travel light years through space to find them.