This is only a partially educated guess from a worm's eye view of FAANGs but if the product is designed to run on a FAANG's internal infrastructure, relies on t

This is only a partially educated guess from a worm's eye view of FAANGs but if the product is designed to run on a FAANG's internal infrastructure, relies on their their internal-only libraries and development processes, etc., it would likely be more effort and risk to undertake the engineering to transform it into a standalone spin off business than it would recoup. Not to mention that key project staff would likely rather stay with the FAANG and initiate internal transfers rather than be spun off, further complicating the process.