Its both:

1. Platforms have a civic responsibility to not promote disinformation.

2. Citizens have a responsibility to escape their bias and bubbles and reject disinformation.

But in the current environment where even basic truth and sources are under attack by yelling 'fake news' where is the foundational truth on which to even arrive at critical thinking?

This is the authoritarian's great trick.

Critical thinking is hard work and discomforting, its much easier to pick a side and allow yourself to be manipulated.

We need critical thinking but more importantly we need to attack the tribalism and polarisation that prevent us even making the journey to critical thinking.