It would be difficult to get the same effect in live-action (whether film or on stage) that Eisner gets by his lettering. Words emphasised or getting smaller, jagged letters, dripping balloons, even the way consecutive word balloons lead into each other. And the way the reader can take in the art and words at a chosen speed, rather than have it forced upon him. This, and sound effects, are some of the reasons I love comics as an art form in their own right.