That isn't true. Copyright does not just protect "concrete versions". For example, here is a famous court case[1] in which one of the criteria was whether a "ordinary reasonable person" would find there was substantial similarity between the two works. Some of the similarities can be as vague as "McDonald's character Mayor McCheese and Sid and Marty Krofft's character H.R. Pufnstuf both are fictional mayors that possess disproportionately large round heads."

[1] - https://en.wikipedia.org/wiki/Sid_%26_Marty_Krofft_Televisio....