If Valve’s Employee Handbook is to be believed, they don’t use a formal project structure with static teams. Instead each developer works on whatever project interests them, and one of Valve’s current goals is to improve game performance on Linux/AMD by contributing to upstream open source projects.
Valve is as close as we’ve gotten to someone paying a bunch of industry veterans to contribute to open source. It’s amazing what happens when all innovation isn’t black-boxed in an internal repository and forgotten about.
The downfall began when Ubisoft abruptly wrote Lucy out of the story after Kristen Bell asked for more money. Then they killed off the literal main character one game later, and nowadays you’d be excused for forgetting Desmond ever even existed given how little the modern day matters to the plot.