In a sense - yes it is good to 'be like everyone else'. Now before you all downvote, ask yourself what do we consider normal? When becomes a behaviour problematic?

we assume behaviour falls on a bell curve. At the extreme ends is behaviour that's is considered to be 'abnormal' as in not normal and in the in-between is what we consider normal and what most people do. Abnormal does not mean bad or detrimental to one's health however; it often sparks a negative reaction from others.

In line with this is the 'insult' to be extra unique, different or special would be not normal because most people are not at the end of the bell curve.

If we apply this to mental health: you may feel depressed at times. Doesn't mean anything but the more days you feel that way, the further to the end of the bell curve do you move. At some point you are an outlier and we can safely say: you have a major depression. Now this is simplified but it gets the point across.

In other areas it is better to not be extremely unique, too. Think of school, in my experience being different is not a problem but being extremely different to your peers will have negative impact on you. They might pick on you or outright ignore you. This is not justifying this it is sadly how it often goes.