If I were to read 10 victorian crime novels that all involved murder and were all first person and then write my own first person crime novel, have I plagiarised the originals or merely been inspired by them?

This is how I see AI. Having read hundreds of millions of books it can then write its own. Its not copyright theft or plagiarism. If it has been fed content on the internet a human can read (or watch?) for free then no loss of earnings has taken place.