I understand, but 1.1.1.1 was used by people for internal use, for example as a default for portals on wifi routers. Because of that, now anyone that wants to use the 1.1.1.1 DNS server can not when they are on wifi routers that use that IP as the traffic does not go where it was intended.

For example, my username is enzanki_ars. Let's say I set up enzanki.ars at home as a host for an in home only server. Now let's say that a new country registers .ars as a new TLD, for example Argentina as ARS is the ISO 4217 currency code for the Argentine peso. Now I am stepping over someone else's TLD, an someone could even register enzanki.ars before me and start using it.

My personal policy is "just because you can doesn't mean you should." If I wanted to disrespect the process we have in place to prevent people from stepping over other people's domains, I would have set up enzanki.ars already. Until then, 192.168.0.0/16 is how I reference my hosts at home.

Edit: See also: https://www.iana.org/assignments/special-use-domain-names/sp... for an up to date list of special use domains. "home.arpa." was recently assigned as one, and I may start using that one at home.