You know I’ve said “dude” all my life and I still use it all the time in regards to everyone. If I saw that someone was genuinely offended at being called dude I wouldn’t use it again with that person, but now that I really think about it I don’t think I’ve ever heard the term in a derogatory way. Like ever. For me it’s always been a happy/inclusive word for addressing friends. My only worry for now is that saying it shows my age.