Not only are we starting to look for these kinds of things, we're rapidly getting better at it in terms of precision, accuracy, understanding, and rate. There are around 30 billion stars in the Milky Way that could potential have a truly Earthlike planet orbiting them (not Earthlike as astronomers use the term, but as in theoretically the same in all the characteristics that caused us to be here talking about it).
Would like to see some references, and your qualification of "Earthlike" There are 100 billion stars in the Milky Way. You are claiming 1/3 of them have potential for Earthlike planets.
One of the big problems is outer gas giants kicking out the rocky inner planets by inward migration - our solar system may be rather rare in that regard - Saturn. just happened to be in the right orbit to prevent Jupiter from doing just that.
It could be less than 1% of systems even has rocky inner planets. So know we're down to a billion.
Then you have the other filters which we don't know about - e.g. perhaps the early collision with what later formed the moon was necessary to generate plate tectonics, and events like that are rare or don't occur early enough in the life of the system