Yes. And maybe the very worst stayed to play havoc in our development. Perhaps, some of the best stayed.
Discussion
Right on! You should read Alien Interview. It’s supposedly a journal kept by a nurse who took care of one of the Roswell Aliens. It’s free online. Even if you don’t believe a word she says as truth it is still a very compelling sci-fi plot.
https://archive.org/details/alien-interview-lawrence-spencer-matilda-mac-elroy