I typically decline the pre-departure beverage when flying up front, and honestly on a lot of US airlines these days it's inconsistent as to whether it's even offered. So both I and flight crews are trying to avoid inconveniencing you :)
Also, on international flights this won't interfere with the boarding process, because usually they either board using multiple doors (one for business/first, one for economy) or they board from a door behind the front cabin, so that people in first/business turn left to get to their seats while people in economy turn right. There are some studies suggesting that if people don't have to walk through and see the fancy cabin on their way into the plane, they get less angry in the economy cabin.
That said, yes, it's a very different world. I've done international flights in economy, and suffered. I've also done them in business class, and was fine. Getting a good night's sleep over the ocean, stepping off the plane into fast track through immigration, then into a lounge for a shower and a hot breakfast, makes the process not only bearable but pleasant.
And that's without getting into the ultra high end of airline travel (which is still well behind what you get once you're into private-jet money). Look up some videos of, say, Lufthansa's first-class terminal in Frankfurt. It's literally a separate terminal for the first-class passengers, with private security screening, private passport control, private dining and relaxation areas, and then they put you in a chauffeured luxury sedan and drive you across the airport to your gate, where you take an elevator up and board the plane, never having to mix with the economy-class passengers at all.
The middle eastern carriers are like this, too, and many go so far as to send a personal driver to your home or hotel to pick you up and make sure you reach the airport in time, and have staff who whisk you through check-in and security and into a private lounge to wait for your flight.
Currently Etihad has the fanciest in-the-air setup, with two different first-class "seats" on their A380s, both more or less private airborne apartments (one of them is literally called "The Apartment", the other is a multi-room setup called "The Residence"), with your own private butler, access to a shower in flight, etc.