Condour75's point was not that if Peter Pan was copyrighted that we wouldn't be seeing movies featuring the character, but rather that we wouldn't see this type of Peter Pan film. Here's one description of the film,

Neverland is...an innovative interpretation of this ultimately fantastical story of hope and sorrow, a psychedelic ride through the adventures of the Darling children, strewn with transgendered Indians, pirates with leather fetishes and bits and pieces of the original dialogue thrown in for good measure.

I don't think if, say, Disney owned Peter Pan that we'd be seeing a Pan film featuring pirates with leather fetishes.

One of the problems with copyrights in perpetuity is that we have all of these iconic characters that are now part of the culture that are also completely creatively frozen because the best way to exploit such a property is to turn out the same safely boring derivative product every two or three years (like the Disney's excrable treatment of its Winnie the Pooh franchise).