In a sufficiently expressive language, do-notation isn't that important. Consider the following pieces of (equivelent haskell)

    f1 = do 
         fd <- openFile "/file/path"
         contents <- readFile fd
         let result = process contents
         closeFile fd
         return result

    f2 = openFile "/file/path" >>= \fd -> 
         readFile_ fd >>= \contents ->
         let result = process contents in
         closeFile fd >>
         return result

Sure, the code for f1 is easier to read, but not by that much. You have a bit more noise in each line with the explicit operators being added. The only big readability difference I see is that you have moved to bound variable to the end of lines instead of the start. I've never actually worked in a codebase that regularly did this, but I suspect you would get used to it frequently. The inconsitency with let statements putting the bound variable on the left would be a readability drawback; but I can easily imagine a language that allows for putting the bound variable on the right hand side of an assignment, such as (not Haskell):

   let process contents -> result in