We see the protodeacons in Acts 6 when there is a dispute between Hellenistic wives and Jewish widows about poverty relief. In order to allow the Apostles to do what they are supposed to be doing—namely, preaching—there is an election of what I would think of as protodeacons. Seven men are chosen.
The elders of a church rule and deal with issues of doctrine and shepherding, but every church has all kinds of practical things to do, including the distribution of food. During COVID, our church distributed a lot of food to people who were shut in, and that’s best done by deacons. A church with good, godly deacons can work far more efficiently.