The 1970s was a mixed bag. It was the Grindhouse era, it was the Dirty Harry era, the Godfather and Star Wars era, but also the era when movies like Ordinary People or Kramer vs. Kramer were box office hits.
The studios were still taking potshots, hadn’t quite codified the Formula yet. Nowadays, the big studios all belong to marketing and their laundry lists of what movies are worth investing in.