I have seen a number of less competent people move up the ranks. While they were not good at work, they certainly knew how to play the social and political games. And I saw them mess up their new positions big time before moving on.

I believe this will always be with us. You cannot stop it from happening unless you get in a position where you can make sure these folks do not rise to their own level of incompetence.

But what you can do is to increase your own odds of moving ahead. By doing your job and doing it well, by joining the social niceties, and by letting people know you are ready to move up and deserve it, you will increase your odds of moving ahead. If you just do your job and do it well, that is where you will remain.