Haskell allows this too, users can just code everything within IO until they feel comfortable with adding extra purity through refactoring:

    main :: IO ()
    main = do
        myBusinessLogic
    
    myBusinessLogic :: IO ()
    myBusinessLogic = do
        doThing1
        doThing2

    doThing1 :: IO ()
    doThing1 = do
        putStr "Hello "

    doThing2 :: IO ()
    doThing2 = do
        putStrLn "World"

    ---
    ghc -o main main.hs
    [1 of 1] Compiling Main             ( main.hs, main.o )
    Linking main ...
     ./main
    Hello World