Keep in mind that if the plane was more than a year or so old, the fault lies with the airline maintenance, not the manufacturer.
The last two were built in 2005. So unless it was one of the last two on the line, it’s more than 20 years old.
I am well aware.
A friend of mine works maintenance for United.
But this is but a small part of what I am thinking about.
Many things that have happened lately are directly linked to Boeing.
Likely, but...
The manufacturer, in this case Boeing, determines the maintenance schedules for the various components.
Boeing oversees recalls for components. The maintenance teams aren't going to swap out parts that haven't been correctly flagged for recall.
Boeing oversees the contracts for replacement spares that are only available through Boeing. Much like the "dealer item only" parts, the maintenance teams can only source certain spare parts through Boeing.
Some of the original parts from Boeing have been counterfeit.
https://gizmodo.com/boeing-planes-fake-titanium-faa-investigation-1851541451
While the spec'd component might have been rated for x hours or flights, the counterfeit one might last years and then fail before the maintenance teams detect anything wrong with it.
An original component may have a shortened lifespan if a later change to a connected component is modified. (Component A is rated for x flights but if attached component B is replaced with an upgraded version, component A now has a shortened lifespan). The maintenance schedule on component A won't change unless the engineers at Boeing identify it. Changing the weight of components to any significant amount will certainly impact the landing gear.