My old touring bike had probably 4000mi from me. It was a frame I bought here from the C&V forum- a 1990 touring frame built by Fuji for a private touring company. Built it up almost 5 years ago with a mix of old, middle-aged, and new components to fit what I wanted. I sold it to another C&V forum member a few months ago. Most all my touring is weekend trips, so 2-4 days and 70-300 mi in total, so the miles dont pile on quickly.
My current touring bike is my old gravel frame- a Black Mountain Cycles Monstercross frame. It has all the rack and fender attachments, fits great, and is lighter as well as stiffer than my old frame. I built it up with all the components from my old touring frame. I think everything is from the old frame except for some headset spacers and the canti brakes. I kept the old SunTour canti brakes that were already on the gravel frame.
That frame has probably 3000mi on it so far? Not sure exactly.
Like so many others have mentioned- its tough to say what has the miles on it- the frame, components, or both?