Agree that doing nothing is wrong. Left alone the behaviour becomes the norm and can even work its way into relationships outside the actual parties involved. I worked at an organization where certain categories of job titles could be treated like dirt and other seemingly caring staff could turn nasty on a person based on nothing but a simple written policy.
Sadly, I think most people are cowards and many forms of bullying are acceptable. My experience is though standing up to bullying is necessary it comes with the cost of being shunned for not accepting certain twisted social “arrangements” as not to be talked about.