Never build your life and identity around one person, especially if that person doesn't feel the same way you do. Instead, try to realise who you really are.
Equality will not exist as long as one of the groups is at a distinct disadvantage.
No one can please everyone and be perfect. Everyone does their best to cope with the pressures of society.
Toxic, supremacist ideologies do no more good for the people who espouse them than they do for those they oppress. Both Barbie and Ken are ultimately unhappy and dissatisfied with the gender-supremacist systems they live in (and in Ken's case, create), and Ken explicitly admits that adopting a hyper-masculine lifestyle under patriarchy has not made him happy in the way that simply being able to be himself would. Also, mini-fridges are annoying and inconvenient, and it turns out that patriarchy as a concept doesn't have much to do with horses.
Power is the ability to live your life as you see fit, considering others and staying true to yourself, rather than just being in charge. Both Ken and the CEO of Mattel recognise that being a leader is difficult and yearn for simpler pleasures.
The real world is a complex, often dreary and frankly unfair place, not at all like the sanitised, overly idealistic world of children's toys. And that's okay.
Change is an inevitable (and difficult) part of life, and we must embrace it.