Was bevy considered?
I'm surprised Toyota even used something as new-ish as Flutter. Carmakers usually are the last to adopt anything.
Bevy is the opposite of an old boring solution. It's a cool engine, but I imagine a manufacturer would like to have long-term support with 15-year timelines. Bevy doesn't offer that, and even trying to have that wouldn't be good for Bevy.
I don't think anyone's seriously using Bevy's 3D renderer, only the ECS. The only successful 3D game made with Bevy so far seems to be Tiny Glade, which used its own renderer.