• Because a lot of the content on national TLDs is relevant only for people of that nation. It helps with name clashes and pushes off stuff that doesn’t make sense in any of the more “global” TLDs.

    And for governments, banks and other institutions there should really be some official standard where they pick a single second-level domain and use it for stuff that needs to be secure so anyone anywhere can be sure it’s controlled by the correct entity and not a scammer.