> DNS requests are routinely intercepted and monitored by ISPs in many countries, with the information available to the security services
Not true. ISPs typically record and store netflow-like data, very rarely DNS-data (I'd say storing DNS data is even unusual). If ISPs are in a position to get more detailed than netflow data on you they resort to things like deep packet inspection (DPI), which doesn't rely on DNS, pretty much all mobile/cellular ISPs do that today.
> DoH is vital to protect users around the world from censorship and worse.
Not true either. DoH can't do anything against censorship and if enabled by default in all browsers can actually give worldwide censorship powers to a single US entity that already has something akin "we will block anything we don't like and do anything our government wants" in their ToS.