Not only have our signals not traveled far by even galactic standards, they have to deal with the inverse square law. In other words, as the signal radiates out, it weakens relative to the amount of space it's now "occupying." We've sent out tight beam transmissions, but even those have to deal with the same thing over the huge distances it will traverse.
Space is big.
And even if there are other civilizations, we have to coexist temporally to communicate. So, not only do we have the distance factor, we have to think about how long a communication-capable civilization will survive.
Time is short.