Those Hollywood execs work for giant conglomerates that own a whole host of media properties including television stations. If the CEO of UPS, one of the largest, if not THE largest, shipping companies in the world, called up Viacom, for example, and said that UPS is going to pull advertising from all Viacom owned entities if they don't give into SAG-AFTRA and WGA demands, that would do enough damage to potentially end the strike. It would cost Viacom millions of dollars on top of what they're already going to lose from the strike.

But UPS isn't going to do that because if striking works for anybody, they might have to pay their workers more.