Don't most devices use just DHCP, which in turn in most cases just use the DNS settings of the Internet Provider (IP) that is being used (indirectly, as usually

Don't most devices use just DHCP, which in turn in most cases just use the DNS settings of the Internet Provider (IP) that is being used (indirectly, as usually the local router is set like that) => if a local government asks the IPs to use specific root servers then the problem should be solved? (or maybe I'm not understanding the core problem...)