“Episkopos is just another Greek word describing one duty of Elders of the Church.”
No. The same root word is used in regard to the replacement of Judas. Thus, the bishop is a successor to an Apostle when most properly understood. Otherwise in the NT the word is used interchangeably with the word presbuteros (elder/priest). Distinctions might have come later - obviously - but that is not out of keeping with the NT.
“Five different words are used to describe the main duties of this office.”
And even so, as I said, in Acts 1 we see the clear link between the office of bishop and Apostle.
You have never studied Greek or Hebrew? If you have, you are rusty, based on your post. The root does word does not equate what happened here with the official church office of Elder.
Beyond the improper use of Greek to justify a position that happened after 100AD, when the Apostles chose a replacement for a traitor Judas, they listing this criteria, which never occurred again - nor can ever occur again...
Acts 121 Therefore it is necessary to choose one of the men who have been with us the whole time the Lord Jesus was living among us, 22 beginning from John’s baptism to the time when Jesus was taken up from us. For one of these must become a witness with us of his resurrection.”
23 So they nominated two men: Joseph called Barsabbas (also known as Justus) and Matthias. 24 Then they prayed, “Lord, you know everyone’s heart. Show us which of these two you have chosen 25 to take over this apostolic ministry, which Judas left to go where he belongs.” 26 Then they cast lots, and the lot fell to Matthias; so he was added to the eleven apostles.
Here is a list of the requirements:1. a Man
2. Someone who had been with the group of Apostles
3. During the physical Life of Christ
4. Specifically, from John the Baptist's baptism of the Savior until the Resurrection
5. And if this were a template, which it is not, since the Apostles were the foundation and not an ongoing office, TWO were chosen
6. Prayers were offered and a request to show who the LORD CHOSE
7. LOTS WERE CAST to reveal the answer.
It should be added that nowhere in Scripture does God command any other Apostles to ever be chosen.
Nowhere in Scripture are there any examples of Apostles being chosen again.
Nowhere in Scripture are there instructions for choosing Apostles.
Scripture only records qualifications and instructions for choosing Elders and Deacons.
PS - ain’t no church office of priest in the Church either.