It can be used to keep bad content away from kids. DNS over TLS can be blocked on the network router / firewall and DNS safe search enforced by forwarding lookups to something like Adguard
Enterprise and school devices often configure browsers to not allow modifying DoH settings and configure the OS to not accept unapproved programs like sideloaded browsers that may not obey that device policy.
> Anyone can change their DNS and use DNS over https
Not if the machine is locked down. Blocking all search engines is not a feasible approach, though, hence the Safe Search mechanism.
> Also blocking the search is pretty weird, what prevents me of typing the URL directly?
That URL can be blocked at the router level, but one can still see cached search engine images when safe search is off.
Also blocking the search is pretty weird, what prevents me of typing the URL directly?