I'm 41 and find the Steaming selection while large mostly B movies or old titles. Typically anything you'd go to a B&M store and find dust on. If you really like old, foreign, obscure, or indie stuff then they have plenty of content for you. If you're looking for stuff typically released in the last year... not so much.
My 5yo daughter finds the kids selections 'ok'.
It's good if you want to watch old TV series though.