Let me break it down for you. It's evident you don't know the details. At the time, Val Kilmer was known for movies like "Top Secret" & "Top Gun." An actor who looked nothing like Jim Morrison. There was high doubt he could pull it off. Yet, he became Jim Morrison on the screen. Not only did he pull it off, but the guy actually sang the songs in the movie. He didn't lip sync. I still feel he should of gotten a nomination for that role.
Micheal Keaton was a comedic actor. I remember the first question a lot of people asked in 89' when they heard he was playing "Batman" was, "Is it a comedy?" And chuckled as they asked.
Robert Downey Jr. great actor, but had slipped under the radar due to his personal issues with drugs. "Iron Man" was his comeback role after years of being on a hiatus.
So yes, I'd say it is a meaningful contribution to this discussion.