Earlier quoted context omitted.
Part does not just mean discrete object. The lower part of that beam is damaged. pärt/Submit noun 1. "a piece or segment of something such as an object, activity, or period of time, which combined with other pieces makes up the whole." 2. some but not all of something. "the painting tells only part of the story" You might be thinking of Component, but even that's arguable. CPU's often contain nonfunctional parts so e…
This discussion isn't about parts, components, or any other pedantic segmentation of matter; it's about the consumer's ability to perform maintenance.
Early CPU's where built to be maintained, modern CPU's are not. That in no way makes modern CPU's worse. The Hubble cost more to maintain than it would have been to replace with something better. From a utilitarian standpoint the ability to maintain it was useless, from a political standpoint NASA loved being able to pretend those missions where useful.
At a deeper level maintenance generally means some parts break down before others. So, an ax becomes less sharp over time. Meanwhile the head also loses strength which limits how long that head can reasonably be maintained.
QED: Maintenance is all about having different parts that ware out a different times.