In answering “If aliens really exist, why don’t they visit Earth? Do they fear humans?”, at least we agree. They aren’t visiting. But why not?
I suggest because they are in a galaxy far, far away and light speed is just plain pokey.
Even though we want to go faster than light (FSL) for making cool Star War and Star Trek movies, the reality is that not only is light speed impossible, getting close to light speed is impossible. It would take infinite energy to accelerate to the speed of light.
Even if you could go as incredibly fast as, say, 1/20th the speed of light (highly unlikely), it would still take 800 years to visit the Trappist-1 system with seven Earth-size planets. It could very well be that Trappist-1 has no life. More likely we would have to go out a lot further, perhaps across the galaxy or billions of light years to other galaxies to find intelligent beings.
Those alien beings have the same problem we have. We both suspect the other exists, but neither will ever know for sure because the distance is too great and the speed of light is too pokey. All we can do is imagine.