Many action movie franchises began with an R rating but then changed their tone and content to garner a PG-13 with later installments. The first movies in these series, many of them from the '80s and '90s, incorporated gory violence, foul language, and sexually explicit content, but as the franchises continued to spawn sequels into the 21st century, such R-rated material proved limiting in box office appeal. Despite mixed reviews for the watered-down versions, PG-13-rated sequels to preexisting R-rated action movie franchises indeed managed to attract younger audiences and rake in more money.

https://screenrant.com/movie-franchises-rated-r-pg-13-change/