Something which has slipped past most people’s radar is that China recently acted as the intermediary for peace talks between Iran and Saudi Arabia. The two countries have been at each other’s throats for decades, funding and running operations and proxies against each other. Elijah Manjier has a decent summary (part is behind a subscriber wall) from a pro-Iranian point of view.
It’s also interesting that in this conference no English was used!
Now it’s obvious why the US couldn’t be involved: it hates Iran and doesn’t intend to change that any time soon. But that China was reached out to indicates that it has good relationships with Iran and Saudi Arabia and that it’s considered powerful and prestigious enough to be involved a region far from its core.