It's not just a question of laziness IMO. Censorship can also take a lot of bureaucratic work. But it has a reliability advantage that counter-propaganda does not.

Plus, the domestic situation is more important than what some liberals in the global north think. They will always find a way to hate China if the geopolitical situation calls for it, including funding terrorist organizations to stoke a proxy war to help destabilize China and then blaming China for carrying out a successful and relatively humane counterterrorism campaign. There's no winning with these people. All you can do is your best.