First you need to realise that in the grand scheme of things we are very very under-developed. According to "The Kardashev Scale" we are not even a type 1 of 3 (but a around about 0.73 and we are going to get to type 1 in around 100 years)

A Type 1 civilization is a species who have been able to harness all the energy that is available from a neighboring star, gathering and storing it to meet the energy demands of a growing population. This means that we would need to boost our current energy production over 100,000 times to reach this status.

A Type 2 civilization can harness the power of their entire star (not merely transforming starlight into energy, but controlling the star). Nothing known to science could wipe out a Type II civilization. Take, for instance, if humans survived long enough to reach this status, and a moon sized object entered our solar system on a collision course with our little blue planet–we’d have the ability to vaporize it out of existence. Or if we had time, we could move our planet out of the way, completely dodging it.

A Type 3 civilization is where a species then becomes galactic traversers with knowledge of everything having to do with energy, resulting in them becoming a master race. In terms of humans, hundreds of thousands of years of evolution – both biological and mechanical – may result in the inhabitants of this type III civilization being incredibly different from the human race as we know it. There are many theories as to Why havent wee seen/made contact from any aliens but here are the main 4:

They're too Alien
This basically maean that maybe we have met aliens but theyre nothing like what we expected to find. Maybe even if they were right infront of us we wouldn'nt recognise them as an "alien".
They might want to leave us alone and develop by ourselves
The aliens might want to leave us unattedned and study us as we evolve over millions of years. They wouldnt want to come close and let us know that they're there because then we might do things differently.
They dont want to screw us up
Lets say that the aliens had touched down on Earth during the Dark Ages, they decided to try and help. So they gave humanity an infinite resource cube, thereby eliminating the need for any of us to ever compete for resources ever again. The aliens leave, patting themselves on the back for their good deed. However, with endlessly renewable resources, Earth quickly becomes overpopulated, and instead of fighting for oil or whatever, people are vaporizing each other with mooncube lasers just for living space.
We might not be worth their time
We might be so unadvanced that they dont bother interacting with us. For example, when you're on your way to the shop do you stop and look at every ant on your way? Do you care for that ant or try to communicate with it? No, i really hope you dont.

Guys i want to know what you think about why we have never seen or recived word from aliens - leave it in a reply
Upvote and follow for more!

grubbyhat