Long-term for the likes of Hollywood contract studios is "till the end of the production" so, yes. It's also insanity to switch software while a project is ongoing so you'd have to shut down the studio and then start it up again at which point they'd likely be bankrupt. They're not even upgrading software versions.

Now if you're the likes of Siemens or Airbus who more or less on a whim write their own CAD/CAM packages sure it pays off to re-train your engineers, using a software that was tailor-made for what they need to do was the objective in the first place, increasing their productivity. But you won't make a Maya artist more productive by sitting them in front of Blender. It's more like switching between vi and emacs: Both are very capable and have steep learning curves due to their sheer power and productivity focus (and one of each causes RSI. To wit, Maya doesn't have right-click select).