A couple of things, first I am a Pastor so I have a bias towards Pastors.
Last night I taught a lesson on God giving you what you need in a package you don't want or like.
Partly in reference to the Election, the scriptures speaks volumes regarding submitting, honoring and obey authority figures, even when their authority manifests itself unjustly.
I Peter 2 refers to this.
Now if God calls us to submit, pray, honor worldly human institutions, I think the requirement is more significant in the house of God.
A few things about leadership/elders.
In the NT setting Elders (spiritually mature, seasoned, leader) lead or ruled the local assembly, some of these elders were Pastors, some prophets, some teachers etc.
So in essence we all need elders. In their role as Elder they might fulfill as Pastor's role, Evangelist or Prophet, etc.
Their importance is that when Jesus delegated his authority to his disciples he told them on more than one occasion that if one receives them, then he is being received and if one rejects them then he is being rejected. Of course the authority is derived from speaking words of God.
So as I speak the words of God in my local assembly, I represent Jesus and the authority of God word's to them, if they reject that then according to scripture they reject the authority of Jesus in that assembly.
And accordingly if they receive my words (based on the text, legitimate authority) then they are receiving from Jesus as if he was standing there himself.
The power of binding and loosing is a reference to this as well, of course the key word in that often misused passage is whatever has been loosed in heaven then can be loosed on the earth, Elders if it has not been loosed in heaven, you have no such authority on the earth. This guards against mis-use of authority.
But even illegitimate/false ministers can be the vehicle by which the Lord moves, the passage in
Matthew 7 about those that work wonders, miracles, cast out demons, and yet Jesus never knew them is a tremendous warning of being right with God regardless of ministerial results, success or gifting.
Though it is worth pointing out that even with that being said, people did get delivered from Demons, miracles happened and wonders were received by believers. God ultimately judged and held those false workers accountable.
There are many other reasons, but in short we do need Elders, Pastors, leadership, because they do speak in the place of Jesus in a delegated role.