Complex sentence: Nevertheless, Hollywood has been making more action films than ever, partially due to advancements in CGI have made it cheaper and easier to create action sequences and other visual effects that required professional stunt crews and dangerous staging in the past.
Split into simpler sentences: Nevertheless, Hollywood has been making more action films than ever, partially due to advancements in CGI. Advancements in CGI have made it cheaper and easier to create action sequences and other visual effects that required the efforts of professional stunt crews in the past.