Earlier quoted context omitted.
If you're in Europe, there's the newly launched DNS4EU project which is free for personal use, and also includes adblocking at the DNS level like NextDNS. I use it in conjunction with Adguard and secure DNS, but they also publish configuration profiles for iOS. https://www.joindns4.eu/ https://www.joindns4.eu/dns-guidelines
Woah, that looks like an great effort! Never seen before, wonder why they're not making more noise about it and/or use it for more services, probably would have come across it while poking at various EU services DNS configs if so, but haven't so far. Anyone happen to know exactly what the "Protective" option is for/does? I see there is one "Unfiltered", and lots of "Protective + Something" options, which is kind of c…
If you check dns0.eu (free dns service for EU provided by the company behind NextDNS), it says they’ve closed down, and refer to DNS4EU or NextDNS.
As for what the different categories cover, they have the block lists they use linked “somewhere” on their page.