Capture is futile rather than prohibited — and it is also unnecessary, because there is no ceiling on what contribution can legitimately obtain. Those two facts together are what make the structure stable.
Each stop is a page in the graph. The order is an argument — but every one of them is also a door into the rest of it, so you can leave the path wherever it stops being useful.
There is no operator to lobby, no jurisdiction to arbitrage, no process to outlast, and no lever at the center for anyone to hold. The rational strategy for a participant powerful enough to attempt capture is to contribute instead.