I do feel watching movies alone 1)a bit liberating and 2)a much more authentic unbiased experience.
Now the psychology would vary for people, I personally am a bit of a people pleaser, hence I won’t put forward my opinions strongly if the person I’m watching with has different views.
And yes I’ve just started watching movies by myself recently, after the initial resistance and the fear of being judged it all comes down to mitigating that overthinking.