I'd say this is more about being able to identify and crush any nascent political movements that threaten the status quo in their infancy, but no reason not to let the implementers wet their beak to get buy in.
https://cybernews.com/tech/microsoft-dutch-data/
This is precisely the type of surveillance that can be achieved by breaking encryption or by placing local control agents on devices.
A chat control mandate massively empowers big tech and the US government hosting those corporations.