What’s against an engine holding EWIG?

Dear friends, car life depends on VERY many factors. Some people find that a car with 150,000km is already ready for its last rest, some people drive their car up to 600,000km and don’t understand where the others have a problem. Often, a car life also ends with regulations such as diarrhea by the HU due to xyz. Or simply because of the economy, as one owner says, “The repair already exceeds the residual value. In the new. That’s it.” But the heart, the engine. How long can such a person do? Often these are still completely intact. And right, as my common sense says. These are blocks of highly hardened materials, which also glide over each other by means of oil film. Aren’t they like brake pads or tire rubber. So what prevents an engine from running EWIG? 500,000, 750,000, 1,000,000 and more? Yes, I know the old Mercedes that were known for millions of running power. Ht built elements AM motor like control chains that length each other, skip and shut down but the block itself? BACKGROUND With purchase advices or general assessments you hear very different things from people. At 150,000km someone can say “finger off. The engine is already as good as over the Jordan”. Some say with a mileage of 320,000 “Never. With good care, it does at least as much.” Is it possible to change/maintained parts (oil change, spark plug change, timing belt change, throttle valve/AGR cleaning, valve cover seal renewing etc.) so in short carefully everything “in shot”, can the trip go on potentially endlessly? Especially if you do the above things yourself, the costs are absolutely minimal. How do you think about certain running performances, if you look at a used one for example? PS: I am already aware that STARK is also from the If you drive like a lunatic and whistle for maintenance, you will certainly get a car within 60,000km of the scrap yard.