If Anime/Manga NEVER Existed at all it would have MAJOR Repercussions, Total World Change!
Many that say it would have never effected what they grew-up with or liked growing up or like now don't get the point that a Vast Majority of many things we like now that are popular in Fiction/Pop Culture Media has had directed and in-direct Influence from the Anime/Manga Industry.
Their are to many examples to list them all, but a major one:
The Popular 1980's Saturday Morning Cartoons Alone! Many Japanese Animators came-over to work on American Cartoons in the 80's and Everything from Transformers to GI Joe to TMNT and Allot more where cause of the Skills of Japanese Animators, Hence Anime BUILT the Kings of Cartoons in the 80's!
This goes beyond my personal view really, if Anime/Manga Never existed for whatever reason, the MAJOR WHOLE of Our Entertainment and Even Arts Industries and Culture would look as near 100% Different as I could say and all the lesser for it!