askchapo

Your job depends on enforcing the interests of the bosses

Managers are expected to do this when the time comes, but most parts of most management jobs aren't this. Hiring, training, scheduling, resolving (preferably foreseeing) issues, evaluation -- all of this stuff happens in workplaces in AES states, too. Having a manager who at least tries to do those things competently and fairly can be a huge plus for the day-to-day lives of workers.

As for what one does when the bosses call on you to enforce their will? First, you can use your position to frustrate that will, as @CyberSyndicalist@hexbear.net points out. Second, maybe you have to make them fire you at some point -- everyone should have lines they won't cross.

the point is to not be led by our bosses or their underlings. If there’s already a union, you don’t need a manager on your side cause you can instead tell them to take a hike.

Fully horizontal workplaces can work in some industries, but others (classically, a ship) really do need some people to make decisions and others to follow them. I'd rather look at ideas like democratizing workplaces and electing managers than take the line that managers (even ones chosen by workers) just aren't necessary.