Detecting life around an M dwarf would be exotic by solar system standards. It will be more challenging to detect life on a planet like Earth orbiting a Sun-like star. Here's a concept for doing it using a specially designed shade in space to block out the starlight from the perspective of a space telescope floating 50,000km away.
Given the cost and difficulty of carrying out such a project, you can appreciate why many astronomers are focusing on the M dwarfs for the time being, as their planets may be accessible with ground-based telescopes that are being built already. Nonetheless, observing true solar system analogues is certainly one of the ultimate goals of the field, even if it might not happen in the next few decades.
“The universe is teeming with planets,” and Jeremy Kasdin, an astronomer at Princeton University, wants to see them. Not in the way they’ve been detected so far, but directly. He wants to build a space telescope that will image a planet around another star and tell if it harbors life.