alt Hacker NewsSeconded. My experience has been that -- even while still complying with lots of overhead (e.g. government regulations and compliance) -- smaller teams of 1-3 devs move waaaaay faster than teams of 4-10. Could definitely speak to the overall codebase quality or some other factor, but yeah.
I expect it's more that early in projects you move faster, and that normally involves fewer people.
Once projects get bigger they need more devs and also move slower.
Put a team of 1-3 devs on MS Word and see how fast they move...