The Real Reason George Clooney Left ER
George Clooney is arguably one of the most famous men on the planet. He's become known all over for his chiseled good looks and his intrinsic star power, allowing him to lead a bevy of classics from "Ocean's Eleven" to "Gravity." However, like most actors, he didn't immediately jump to the front of the line of famous men; he had to pay his dues, getting his start primarily on the television side of things.
He had recurring roles on the likes of "Roseanne" and "Sunset Beat," but he really broke into the mainstream thanks to a prominent role as Dr. Doug Ross on "ER." Immediately, audiences took notice, with Clooney winning over numerous hearts until the show's fifth season. However, the show went on to have 15 seasons, meaning Clooney departed partway through the show's tenure.
As it turns out, Clooney left the show in its fifth season so that he could focus on his burgeoning film career (via CBR). He was able to star in movies like "Batman & Robin," "The Peacemaker," and "Out of Sight" while concurrently filming "ER," but to take things to the next level, he had to leave his TV roots behind.
George Clooney's career move was seen as a gamble at the time
In today's streaming age, actors effortlessly move between TV shows and movies. It's not seen as a big deal these days, but in the 1980s and '90s, television was seen as "lesser" than films. Many actors would get their start in TV shows before "moving upward" to movies. This can be seen in the careers of Tom Hanks, Robin Williams, and Clint Eastwood, to name a few. And George Clooney followed that precise trajectory.
After making a name for himself on "ER" and proving he could lead a film in the process, he was ready to make the leap into film full-time. It was a gamble that paid off well for the actor, as he immediately endeared himself to audiences with early 2000s roles in "O Brother, Where Art Thou?," "Ocean's Eleven," and "Good Night, and Good Luck." His slingshot into superstardom makes one 1999 article from SF Gate all the more amusing. In it, the writer states, "George Clooney leaves 'ER' tonight on the path to Hollywood immortality, or possibly en route to accidental obscurity." It's safe to say Clooney fell into the former camp.
The article also contains a quote from "ER" executive producer John Wells, who stated how the actor "lost literally millions of dollars by staying on the show." Clooney fulfilled his contractual obligations, so when he finally left to become a movie star, he was on good terms with the people who helped launch his career. Given his fantastic filmography, it's clear he made the right decision.