Ken and his struggles
It was actually funny how movie kept lecturing me how I should hate men and root for Barbies to "show them and put them down" but whole movie I cared only about Ken. He was literally the biggest victim and tortured soul here. And the only one who overcome it at the end and learned a lesson.
Barbie - had a privileged perfect live from the moment she was created. Had her big house and everyone adored her. Threw a huge tantrum when came to real world and saw that no one bows to her privileged ass treat her like an ordinary person instead if princes.
Ken - was created to be Barbies accessory. Thats his only purpose. Didn't even had his own house. Had to stay at the beach doing nothing his whole existence. Was programmed to love Barbie. He didnt fell in love with her, he was programmed to be her partner. Then went to real world and was shocked that people treated him there like he was a real person and not silent accessory. He enjoyed being "seen" and went home to change things. Basically whole movie he screamed that he Was A Person and Wants To Exist. Movie made him villain for that.
I actually liked the ending they gave him. They admitted that he was programmed to love Barbie and doesnt actually love her. And they set him free and let him be a person he wants to be and find his own way. They didnt force this "love ending" for him and Barbie. Since Barbie has no feelings for him at all.