Rulebooks only work perfectly when everything is static. Even then they only work when you also know all failure cases perfectly which you almost surely don't.

Rulebooks only work perfectly when everything is static. Even then they only work when you also know all failure cases perfectly which you almost surely don't. Uber is in a competitive market and can't freeze features for years at a time. Furthermore, it in a growing market which means scale alone will cause new failure points to come up.