But doesn't Ruby also have those builders? Wouldn't it be easy enough for Scala to implement them in a library if they haven't already? Wouldn't Python also provide this type of syntax? E.g. a possible translation into Python from the Kotlin code on the linked page...

    html:
      head:
        title {"XML encoding with Python"}
      body:
        h1 {"XML encoding with Python"}
        p {"this format can be used as an alternative markup to XML"}
 
        // an element with attributes and text content 
        a(href = "http://python.org") {"Python"}

        // mixed content 
        p:
          "This is some" 
          b {"mixed"} 
          "text. For more see the" 
          a(href = "http://python.org") {"Python"} 
          "project" 
        p{"some text"} 
 
        // content generated by 
        p: 
          for (arg in args) arg