This is not a social engineering attack, or at least it need not be. It is simply made a requirement; block any connections to the outside that do not use the certificate. Then people have a choice of no HTTPS (which blocks many big sites) or HTTPS that is MitMed by the government.

Incidentally, the above is why the 'consensual MitM-ing through a root-Cert is a feature of TLS' does not hold op. It is not consensual, it is not even coerced, it is a hard requirement. You could then go into an argument about national sovereignty / complying with local laws, but that is a totally different argument.