The question was less about speed and more about not having the same code duplicated over and over across tests. Which is how I read the article talking about it. Allowing one test to "depend" on another makes it clear they use the same setup (presumably with the second test going "a bit further", but not necessarily).

I wouldn't have a problem with something like

    test-1:
        setup:
            do-the-thing
        verification
            assert-the-thing-happened
    test-2
        setup:
            depends-on: test-1 // tells it to run test-1's setup
            do-the-next-thing
        verification
            assert-the-next-thing-happened

    GIVEN
       Some initial setup
    WHEN
       I run command
    THEN
       The result of that command is what is expected

I actually use the GIVEN/WHEN/THEN keywords in my tests, to make them easier to read