Lots of studios still build engines from scratch for this very reason: get exactly what they want and avoid vendor lockin. A good FOSS engine that gets them 50%

Lots of studios still build engines from scratch for this very reason: get exactly what they want and avoid vendor lockin. A good FOSS engine that gets them 50% of the way there for free? Seems like a pretty good deal to me. So long as the engine can be extended to get the features they want, it makes sense to use a FOSS one instead of building from scratch. Also, inhouse tooling will need to be built regardless, whether the engine is commercial, in house from scratch, or FOSS. If the studios give back to the FOSS engine source code, it creates a virtuous cycle, like with the Linux kernel. Everyone wins.