I've learned "Don't worry, he treats everyone that way" is a toxic reply in the workplace.
If a male colleage is rude to me, I assume it's his problem, and either shut him down or ignore him. Easy.
But if he acts the same way to a female colleague, she has to ask herself "Is he treating me like this because I'm a woman?". Multiply that by 10–20x/week (or more), and it becomes a huge emotional energy drain.
(Ditto for racialised, trans, and disabled people.)