It's also industry standard to do so. I don't think I've ever seen a team outsource something like pathfinding. Maybe in the Unity/Unreal space, which I'm very unfamiliar with. Dependencies are generally speaking not viewed as a good thing. They become vanishingly rare outside of certain things like physics engines, sound engines, vegetation, etc. And usually higher quality proprietary ones are chosen over OSS (though this is changing with physics engines in particular, mostly thanks to Bullet)
NIH is a cultural pillar. Even scripting layers are relatively split on if they're in-house or not. It's not uncommon to find both an in-house fork of Lua + a few other completely custom scripting engines all serving their own purpose.
It's also industry standard to do so. I don't think I've ever seen a team outsource something like pathfinding. Maybe in the Unity/Unreal space, which I'm very unfamiliar with. Dependencies are generally speaking not viewed as a good thing. They become vanishingly rare outside of certain things like physics engines, sound engines, vegetation, etc. And usually higher quality proprietary ones are chosen over OSS (though this is changing with physics engines in particular, mostly thanks to Bullet)
NIH is a cultural pillar. Even scripting layers are relatively split on if they're in-house or not. It's not uncommon to find both an in-house fork of Lua + a few other completely custom scripting engines all serving their own purpose.