As great as Ed is, the wisdom out here is that he can't carry a movie. They'll pay him $3 million to be the second banana in Julia Roberts things. But they won't put up $3 million for an Ed Harris movie.

Summary

This quote suggests that while Ed Harris is a talented actor, there is a perception in the industry that he is not able to singlehandedly carry a movie as a leading actor. Instead, he is often offered supporting roles, even though he may be paid well for these roles. The quote implies that studios are willing to invest more in films led by higher-profile actors like Julia Roberts, rather than taking a financial risk on an Ed Harris-led project.