"why the whole industry needs to negotiate a single contract between one cartel of buyers and one cartel of sellers." Partly because each talent has so little

"why the whole industry needs to negotiate a single contract between one cartel of buyers and one cartel of sellers." Partly because each talent has so little power than each company if they negotiate one-to-one. You can see that in the countries (like Japan) where there are no strong union like SAG to represent majority of the talents. What happens is that talent's agents get a lot of power over both parties (in the case of actors) or the production take advantage of the talents (in the case of writers or staff). Once I have worked for Japanese TV series filming some scenes in Hawaii. The principal actors arrived at 9 in the morning and immediately filming began at the airport scene, then went through all day at various locations until 1am (yes, 16hours straight), then they started filming at 6am of the same day (so actors and staff took only a few hours sleep). They did something like that for 4 days and returned to Japan. I don't think that kind of schedule is allowed in SAG or AFTRA productions. And actors can't change agents easily, for agents have great power in casting (not like in US). In such situations it's easy for agents to go for its own interest and take advantage of actors. The negotiations can be adapted to the new media; I think SAG had a special arrangement for "interactive media" (including video games) so that the company didn't need to re-negotiate every time to reuse the materials.