[eloff]

Yes companies definitely get more inefficient as they grow, for all the reasons you cite and more. I've experienced it first-hand.

Adding an engineer to a team slows down the whole team a little. There comes a point where adding head count actually results in less productivity overall. This is typically countered by splitting up work into various teams with minimal interaction between them. Like Amazon's famous two-pizza team strategy. This is the main attraction of microservices, each team can own their own piece of the code and change it and deploy it without (ideally) having to consult with anyone else.