One reason I'm lookng at full composite campers. No wood on the inside either and no wood in the building process. Yes seals will still need to be maintained but if a leak happens it can be repaired without major damage. If a leak continues without knowing about it..mold, mildew can be cleaned easily if it does show signs of it and absolutely no rot will occur.
I have seen a lot of used Artic Fox campers with damage over the years.
I think they use luan wood behind the fiberglass skin. Once water/moisture finds it's way inside between the two then the bubbles start on the fiberglass skin.