The RCC and the 7 in Rev.

[Rella]

The 7 churches John wrote to in Rev.

Ephesus,
Smyrna
Pergamos,
Thyatira,
Sardis,
Philadelphia,
Laodicea

Assuming that Rev. was written before 70AD... or in early 60AD
these were established churches of the time

Now wiki tells us

Based on contemporary historical data, Peter's papacy is estimated to have spanned from AD 30 to his death, which would make him the longest-reigning pope, at anywhere from 34 to 38 years; however, this has never been verified And he died .

So if the RCC started in 30AD or close... (That ties in with my
studies of Jesus' crucifixion between 28AD or 30AD ]

I wonder why John did not have a letter for them.

Location... i.e. Rome vs Asia Minor (Turkey)?

Or is the assumed reasons the 7 churches were carrying specific messages?

All I know is I am sorely tiered of hearing people say the RCC is the only true church.

Ah... Wiki also goes on to say

Saint Irenaeus (c. 130 – c. 202 AD) explains the Apostle Peter, his See, and his successors in book III of Adversus Haereses  (Against Heresies).[10] In the book, Irenaeus wrote that Peter and Paul founded and organized the Church in Rome.[11]

Paul is said to have lived 5AD to 64/64AD.

Man, he sure had a busy life....