There are different tasks in the church and there is a need for some sort of leadership. The Acts give the impression that the apostles/missionaries (apostle in the sense of someone sent) appointed ‘elders’ as the leaders of a local church they had started. According to what I have read, the use of the names ‘presbyteros’ and ‘episkopos’ was often mixed, both names could be used from the same persons (we could call them ‘elders’). That seemed to be the situation also in Rome. Later the use of the titles ‘presbyteros’ and ‘episkopos’ separated, and the leadership of local churches turned from the joint leadership of elders to the leadership of a single head, with the title ‘episkopos’ (overseer/bishop). This lead stepwise to the current system of bishops and priest, and in some denominations, to a hierarchy with additional ‘top’ titles.
It could be said that there is nothing intrinsically wrong in having leading bishops and priests. The problems start if it is forgotten that in Christ, we believers are all priests. Appointed bishops and priests differ only in the respect that they have been given the responsibility to lead (shepherd) the congregation/church. Otherwise, all members of the church should be viewed equal in front of God, and it should be fully acceptable that any member of the church can for example, distribute the Holy Communion or baptize. For the sake of unity in the congregation, it is often expected that baptisms happen with the consent of the leader but even that is more of a practical guideline than a doctrinal issue. There is nothing holier in a church than the members of Christ, the believers.
I know that some denominations teach in a different way but I assume that most pentecostal churches would agree with the above. As this thread discusses especially about communication with pentecostals, that needs to be remembered.
Another matter is that many pentecostals are not very doctrinal, they are more interested about the acts and guidance of the Holy Spirit today than what theologians ponder in their chambers or what kind of decisions church councils have made. They keep the biblical teachings as they understand them but rely more on what the Holy Spirit opens from the scriptures than what theologians think about the texts.
Although that may describe many pentecostals, a growing proportion of pentecostals are seriously interested about proper interpretation of the scriptures and theology. A growing proportion of leaders have gone through a theological seminar and are therefore better equipped to deal with theological questions.