It also depends a lot on what type of ICE we are talking about. A very high power output downsizing engine with two turbochargers, direct fuel injection, EGR, intercooler, electric oil pump(s) (for turbo cooling), variable valve timings and/or lift systems etc. -- what you'll typically find in a high trim ICE mid-class car -- has far, far more parts and experiences a lot higher stresses than e.g. the naturally aspirated port injection engine you might find in a city car.