Waaaaay to many variables at play to put a "this is going to happen" on your friend's bike. Generalities are that friction & moving parts eventually wear out, things like fuel pumps, water pumps, t-stats, etc crap out after a few years and many thousands of miles - but then some just keep going. Sensors can fail, bearings can puke, but maintenance, riding condition, manufacturing quality, and pure luck can tell whether your stuff goes at 15k or 150.
Anyone's anecdotes are only as good as those variables worked in THEIR machine.
Never met a dog I didn't like, a machine I couldn't break, or a woman I couldn't tick off.