And if neither Sony nor Paramount are showing movies to customers with iOS or Android devices, one or the other has a huge incentive to be the one to start, even if it means no DRM.

And there are a lot more little studios than there are browser or OS vendors, so there would certainly be movies available. Which would put pressure on more studios to make movies available, which would put pressure on the remaining studios to not abandon a proven revenue stream etc.

I'm also not sure how the argument that people will pirate Hollywood content rather than watch independent content on devices that don't support DRM is supposed to improve Hollywood's bargaining position. It's pretty much the pure distillation of the point that offering content without DRM will reduce piracy and increase revenue.

And "companies with abusive practices are very profitable" sounds like the argument for platform vendors restricting the abusive practices.