One has to realize that people have done expedition type touring all over the world for many years going back to the first recorded touring event in 1869 with 3 people on steel bikes, and people still do to this day with very little in the way of frame breaking, and expedition touring puts a greater demand, thus stress, on frames than just regular touring around a few states in America, or even touring the USA, because in the USA you're never far from someplace to get supplies, but in other countries that won't always be the case, so you have to carry more supplies with you.
And you have to know that prior to the 1980's steel frames were not that great, but they really weren't that great in the 1800's! And camping equipment weighed a lot vs todays ultra light stuff. The trip done in 1869 was not a long distance trip just 15 hours but it caused a revolution to start and by 1890 2 riders took off for a 19,237 mile trip that took 2 years and two months, and back in those days stores weren't everywhere, in fact they were far and few between, they carried a hunting rifle to get food! In addition to all of that paved roads didn't exist, be like taking a heavy low end gravel bike and try to do a 19,000 mile trek on it, yet those bikes held up!
On a expedition trip you can expect to be carrying about 110 pounds of gear plus your body and the bike weight. For bike packing like I do, I carry around 60 pounds in gear, plus water. I don't have expensive ultra light gear either, I could probably drop about at least 8 pounds off if I changed a few items, but for now I'm just practicing for a trip across the USA, when the time comes closer to leaving I will make those changes, but that's 3 years off yet.
