I think they did say that in the older thread. But for proper security, you shouldn’t have to trust them. You should have build tools that will re-fetch everything to create an identical build. That gives a clear chain of custody, which proves that morning has been tampered with.
Two different concepts.
You’re talking about work slowing because of increased overhead from more people needing to communicate and make decisions.
The OP is talking about the"bus factor". How many people can leave the project unexpectedly and still have the project survive. E.g. if only one person has access to merge changes, the bus factor is 1 regardless of how many people actively contribute.