And when you need to fire your friend, or report them for inappropriate behavior in the workplace, how is that going to go for you? What if you share something important with a coworker-friend and they dislike it? You are now stuck with that person.
I’m not sure what you mean by “something important” but I don’t think that’s significantly different than a risk you might take with a neighbor or a classmate. You can be stuck with those as well.