What always amazes me is how the modular engineering of the big HD V-twins is often overlooked. There's a lot of other motorcycles out there that have such a unitized engine construction, that if they have major issues, the whole thing either gets scrapped or needs VERY expensive machine work because everything is cast together and the bearings are the parent material. Motorcycle engines with the cylinders and case halves cast as one piece come to mind. A lot of the HD engine wear surfaces/
parts can be replaced with hand tools; no machining required.
For that 'lifetime' bike, I think HD has the upper hand (at least the older ones) for that being a reality. Live to ride, ride to live.