That's a huge reason to do it also, but it also makes sense if you have researchers + developers improving the engine of something that powers your product. The moat / competitive advantage at FB is their network, not so much the proprietary underlying tech.
People often say this but having interviewed ~200 facebook engineers over the years, their scaling tech around both software and hardware is pretty impressive.
Yeah I guess it's a competitive advantage when a competitor (Twitter) is showing to have technical problems operating at global scale with a smaller team. Their scale is not trivial by any means. But people aren't going to go to FB because they have the best LLM, makes sense to offload that development to the open source community.
