Chained ifs add a whole lot of visual noise, aren't guaranteed to be total, and introduce the temptation to add more logic into the cases.

That said, I do wish more languages had copied Haskell's guard syntax for this kind of chain... For reference, that looks like:

    cmp x y | (x == Nothing || y == Nothing) = NaN -- (assuming x and y are Maybe, but this would typically be non-idiomatic)
            | x < y = -1
            | x > y = 1
            | x >= y = 0 -- inert bug copied from original, "should" be == instead
            | otherwise = NaN

I too always find myself wanting features from functional languages, I haven't done much Haskell but love the syntax for pattern matching in Elixir with guards, plus the pipe operator.

This would be a perfect case for a match expression, which, surprisingly, PHP now supports:

  return match(true) {
    $a == null && $b == null => null,
    $a < $b => -1,
    $a > $b => 1,
    $a == $b => 0,
    default => null;
  }

I’m surprised this feature isn’t prevalent in modern languages. It makes the code so concise and easy to understand, it’s marvellous.