I believe it is in our human nature to always have a "system" to organize people, complete tasks and achieve objectives. The clergy/laity divide is just one small part of that system.
The system looks like this: People at the top who tell others what to do but don't listen, people in the middle where there is conflict between those who see the need for change and those who want to keep the benefits of the status quo and those at the bottom, where most have lost all hope.
The system works like this: hierarchy, formal use of power and authority, routine and mechanistic ways of getting things done and a predominance of one-way communication.
The system is competitive, divisive and readily facilitates corruption .... I think that is why the Lord had a "system" in the OT to show us how useless the system is for His work. In the NT the Lord has an "ekklesia" where there is no system at all .... the ekklesia can only function effectively when we by faith, willingly cooperate with the Lord by the power of the Holy Spirit .... the ekklesia is a supernatural spiritual entity, it cannot function at all within a human system.