> Everyone unilaterally making their own decisions creates an inconsistent mess.
Nobody is talking about people unilaterally making their own decisions. We are talking about intelligent people discussing among each other and reaching a consensus together without having someone else tell them what to think.
> You can still overrule it if it’s not reasonable.
If anything, this would be someone unilaterally making their own decision!
The manager is not some sort of superhuman that alone knows better than the rest of the employees together. Maybe the manager has more information than the rest of the employees, but then the manager can share that and the other employees can revise their decision in light of the new information.
> We are talking about intelligent people discussing among each other and reaching a consensus together without having someone else tell them what to think.
You are assuming here that people are competent, willing and able to cooperate, caring about the interest of the company, and are able to act on their decision. It's great but it's an ideal scenario.
Rules and top down approaches usually are not designed for cases like this, assume now that the group has too few senior people so they don't really know what they are doing, some people that don't really care about the company any more ("I have been bitten too many times so I just collect my paycheck"), some people that have trouble communicating together (due to incompatible characters, timezones, or otherwise), and you have regulations inside to company (ISO, ...) or legal requirements that limit your freedom. Then having manager approval before going forward is definitely helping, and the manager taking a big part of the decision is probably actually helping.
Usually groups are on a spectrum between the ideal situation which you assumed and the horrible combination I described. The verticality of the manager taking decision is designed to address the part of the group that is a bit messy, not the part that works well. It's super easy to manage a small group of talented, cooperative and motivated people. The challenge is to ensure groups that are not like this still deliver value, and possibly reach that state.
Nobody is talking about people unilaterally making their own decisions. We are talking about intelligent people discussing among each other and reaching a consensus together without having someone else tell them what to think.
> You can still overrule it if it’s not reasonable.
If anything, this would be someone unilaterally making their own decision!
The manager is not some sort of superhuman that alone knows better than the rest of the employees together. Maybe the manager has more information than the rest of the employees, but then the manager can share that and the other employees can revise their decision in light of the new information.