If citizens still have a capacity to restrict the government via (enforced) laws, it doesn't matter much that the communications are in the clear. You can layer something on top just to be sure, but the foundation is laws and a functioning political system.
If there's no functioning political system, the government will just do whatever, like buying the same data they ostensibly can't collect from commercial providers (who weren't restricted from collecting it because there's no US GDPR).
If a country has a functioning political system, it can just do things like ban gun ownership, introduce mandatory IDs, publish everyone's yearly income, or criminalise calling other people slurs in public and not become an uncontrollable dictatorship. If it doesn't, corruption and democratic backsliding will happen regardless. Hyper-focusing on a few tools and superficial traits of a particular system in a particular moment is myopic.