Often OSS is used not because you want the software, but the software and the upkeep. So even with such a service, you're now just taking code in-house that you have to maintain as well.

Realistically, if it in fact did take 5 minutes to do the cleanroom reimplementation, you could just process updates from the OSS source in realtime.

The people that will take this as a good thing unironically will just have their personal Yes Man do that work internally.