Culture shock - Manager Carta Employee Review

I work at a startup that was acquired by Carta. Morale with my fellow colleagues is low. The culture is completely different and a shock. We went from working for a fun startup where you had autonomy and lovely colleagues to what feels like a dictatorship. The CEO is awfully tone deaf. Can't believe what I am seeing to be honest. Heard rumours from other staff that they get rid of acquired staff quickly if they don't fit in with their culture. How do they expect us to fit in to such a cut throat corporate beast when coming from a nice little startup. We didn't choose this.