It does change people's behavior. Perhaps the average person will use more polite language? But it's not uncommon for me to see dehumanization, threats, and calls for literal mass-murder-of-entire-demographics genocide promoted with polite language. Sometimes used by journalists. Sometimes by academics. Sometimes by podcast hosts. Sometimes by their fans. Sometimes by politicians. All using their real names.
I frequently encounter people using their real name saying my family deserves to die. Who would, in a heartbeat, threaten my employer by dint of a relative's place of birth.
Not having my real identity behind my posts is my only means of keeping myself safe from extremely sick people online who have a culture of intimidating into silence those that express views or belong to a demographic they detest.