What's the benefit for someone with experience to work at a bank or firm?

I'm trying to break into the industry and I keep seeing job postings for advisors with 3 - 5 years or more of experience, all of their licenses, and many even want someone that's a CFP or similar designation. I understand why someone new like myself would want to start out at a bank or firm, but if someone has already been in the industry for years, has their licenses, and is a CFP, why would they want to work for PNC, BofA, Morgan Stanley, Wells Fargo advisors, etc? What could these places possibly offer them that they couldn't get by going indy?