I can say as an anxiety sufferer and avoider of planes is that the discomfort helps me feel grounded (literally hah). It's its own kind of comfort.

Cheers, I thought I was the only person like this :) (also didn’t tie it to my anxiety, but it’s extremely obvious in retrospect. This is too short and elides the own kind of comfort part, but I guess it means I can’t spin out, ruminating on or creating other problems, when I have stuff right here to complain about!)

Exactly. For many, the idea of being able to see England, Belgium, Germany, Austria, Yugoslavia, Bulgaria, Turkey, Iran, Afghanistan, Pakistan and India in one 50 day trip with many similar minded travelers who aren't in a rush is really quite appealing.

Also, with bus travel you could, if you felt like it, leave the trip to enjoy many more local attractions and resume your travels later in a way not afforded by airplane or rail travel.