Browsers and TLS infrastructure have been solving that for a while now, via certificate transparency. Browsers can now reject any certificate that isn't publicly logged. So, yes, they could MITM, and burn an entire CA doing it.

Russia's ROSKOMNadzor has been trying to get users to install its own Root CAs in recent years. About 10 years ago everyone in the west removed CNNIC (Chinese counterpart) roots after they were caught MITM-ing.