Earth has had life for over 3-4 billion years. The galaxy is only around ~100,000 light years across or so, and the furthest light we can see is no older than that. Additionally, the nearest galaxies are millions of light years away, and what we're seeing is those galaxies from that long ago. Any life on those worlds on planets about as old as Earth would be nearly as evolved as life here, so it would be about as visible.

However, what we can see with telescopes are macro scale things, stars, galaxies, nebula, etc. Smaller scale objects like planets are much more difficult to spot, and signs of life are even harder. For all we know, Proxima b (a mere 4.2 light years away) does in fact have life, but we don't have any way of confirming it because our instruments aren't sensitive enough. Now apply that to stars dozens of light years away, or even in other galaxies. We're only barely able to find planets within our own galaxy, though our techniques are getting steadily better, but we have no way of doing the same for potential planets outside the galaxy.

One caveat to that though is that the reason we can't spot life on Proxima b is because it doesn't transit, and we can't use our only available method for searching exoplanet atmospheres without one, whereas with the TRAPPIST 1 planets, they do transit, so studying their atmospheres is possible, though still tricky. It will likely be a further generation or two of telescopes, and the ability to directly image Earth sized planets (circumventing the need for transits) before we can really detect and confirm signs of life in all but the most specific cases.