I would say the overwhelming majority of Christians do not believe in this relatively new eschatological doctrine ( ~ 100 years or so). Not that certain aspects of it aren’t correct, for instance the mark of the beast, not buying or selling without it is expressly stated in Revelation. We see moves in that direction taking place already (Covid has caused a coin shortage, please pay by credit card).All Christians do not believe in the so-called Rapture. I am one who rejects this as an intermediate appearance of Christ. Scripture calls for two Advents:
1. The Advent of Christ born into this world.
2. The Advent of Christ's return at the end of this world's history in judgment. (This is where the verses that some describe as a "Rapture" actually occur.)
But the historic teaching of Christianity from the beginning is that there is only a single return of Christ. Whatever tribulations occur before then, the church will most certainly be here to see them.
“And unless those days were shortened, no flesh would be saved; but for the elect’s sake those days will be shortened.” (Matthew 24:22).
With regards to the United States not being mentioned in Revelation, I think we won’t be around. You’re already seeing Democrats threaten that Washington, Oregon, and California will secede fo form Cascadia should President Trump win re-election and be inaugurated for a second term.
In 1998, Professor Igor Panarin predicted the US would break up into the following separate countries. Although I think he is wrong about where Tennessee and South Carolina will end up, (they will go with the southern states) I think we can see, 22 years later, that what seemed like an absurd prediction at the time could happen.