Management is the Disease

some interesting points raised in the post, but perhaps one should first distinguish between the different types of management:

1. project management 2. people management 3. executive management

i think your argument is mostly towards project and people managers. project managers own the mechanical tasks of scheduling, resource allocation, aligning priorities, assessing status, assessing risk, updating stakeholders, etc. these are important things that perhaps would be wasteful if assigned to a developer. but let's say for the sake of argument that the developers are quite capable of taking on these activities along with development, design, and architecture tasks, which i've experienced, there are a larger set of tasks that typically need to be dealt with that may have nothing to do with the current project whatsoever such as hiring, developing talent, retention, attrition, motivating, refining and building good processes, balancing budget, developing company culture, setting, aligning, and influencing direction, etc. attrition is particularly an example that should most definitely be put into the hands of a manager, i.e. you wouldn't want a fellow employee to decide that you're fired, this is not the easiest conversation, i assure you. and when it comes to raises, how would a team of engineers decide who gets what piece of the pie?

to your point or some commenter's point about managers costing more than developers, i've managed lots of people that have made way more than me. and i've been very fortunate to see both sides of the spectrum in terms of great managers versus dead wood, you can learn a lot from both types. but management, at the core, is dealing with people, and personalities are never easy to deal with, developers/engineers being no exception.

ultimately i'd love to see a flat hierarchy where everyone could self manage and the science of management could be absorbed into everyone.