The other difference of course being that racial slurs were created and deliberately used to be insulting and degrading and to dehumanize people. Calling a man a man is a statement of fact, even if he wants to be called a woman. It is used to keep reality in check. Moreover, there is no way for anyone to know what ideological concepts are bouncing around in one particular individual’s head and to then cater to them, so unless it is a political and policy debate where someone is trying to make a point (as was the case with Ms. Green), 99.9% of the time when someone refers to a transgender dude as a “he” it is not out of malice but because that is what they see. Just watch that video posted above with the trans dude going absolutely ballistic at some poor kid because he called a 6ft jacked bohemouth in a dress a man. And it makes no logical sense to pretend that every single person you encounter actually thinks they are the opposite sex and to walk around on eggshells when addressing them when over 99% of the population is not confused about their identity.
Lastly I would just like to point out that pronouns are not used in direct conversations, so what trans people are really trying to control is your conversations with other people besides themselves. I do not say, “Hey he, let’s go grab a bite to eat. She, do you want to go to the movies?” That is not how English works. You use names or nothing at all when talking to someone. So the whole brouhaha over pronouns isn’t about being polite to an individual in the moment but about forcing everyone to acknowledge and play out a fiction all the time for one individual whether they are present or not.