The point is there is quite a lot that there is no agreement on, including among the people who supposedly are the ones being offended against.
It is one thing to say something to someone who is, say, shouting real racial slurs at people, and another to call someone out for using a word where there are a lot of different opinions on the issue.
There are lots and lots of people who are not white, who belong to racialized groups, are PoC, who come from oppressed peoples, who don't buy into the typical American influenced stuff around CRT, cultural appropriation, and all the rest of it. There are even a fair number who hate it.
With this kind of thing I think a good rule of thumb, though it's not perfect, is to ask yourself, is there actually real substantial agreement on this among this group, and would I call out a person who belonged to this group for having this opinion? If you wouldn't, you maybe shouldn't call out anyone else over it either.
Cultural appropriation is a good example. With the exception of what you might call sacred objects or depictions that are overtly intended to be derogatory, there is a huge difference of opinion on this, especially outside the US. Even in the US, the people who are most likely to believe in cultural appropriation as a concept are white, Democrat, middle class, voters.
That being the case, calling others out on it is twattish. That doesn't mean it's not something that can be discussed, but that it totally different than calling people out.