Then you need to read your Bible a little closer.
If the RCC doesn't believe they are the Harlot, who do they say it is? The RCC has copied many things of the Babylonian religion. They killed more saints than all other entities on earth. That's what astonished John in Revelation. There were no popes until Constantine in the 300's AD. There are many more indications but I'm wasting my typing if you won't even read it. The fate of the church at Thyatira awaits you if you won't change.
Blah blah blah
The Whore is apostate Jerusalem. The Beast is pagan Rome.
Five kings have already fallen, the sixth now reigns, and the seventh is yet to come, but his reign will be brief
If five of these kings had fallen in John’s day and one of them was still in existence, then the Whore must also have existed in John’s day.
Yet Christian Rome and Vatican City did not exist in John's day.
However, pagan Rome did have a line of emperors. Most commentators see this as the line of kings to which Revelation 17:10 refers.
Hope this is helpful.