The "complicated-subsystem" is a part of the shipped software, it is there to deliver value to the users of the software. The "platform" is there to allow team

The "complicated-subsystem" is a part of the shipped software, it is there to deliver value to the users of the software. The "platform" is there to allow teams to ship software. It is there to deliver value to other teams. I think this second one is what is meant by "enabling" i.e. it's not "delivering value to the users", rather, enabling other teams to do better at that. from the article: "A platform team enables a stream-aligned team to deliver work"