I think a critical component of making platform teams work is to allow internal competition between the platform team and the stream-aligned team using some other technology. In this way the platform team is a stream-aligned team whose customers are internal, and they have to win or lose within their market (internal teams). For example, a stream-aligned team can either use platform team CI/CD or github actions.
What I've seen is that platform teams work well in either small scale (because focus is clear to all) and large scale (because of this internal competitive dynamic) but are extremely hard to execute between the two.
What I've seen is that platform teams work well in either small scale (because focus is clear to all) and large scale (because of this internal competitive dynamic) but are extremely hard to execute between the two.