How long complex things last is also a function of how well you maintain them. A farm tractor, for example, is usually expected to last 50 years or so ... if carefully maintained. A used tractor can have significant resale value at 20+ years if well-maintained. A farmer has very different expectations, both in terms of maintenance put into a tractor and its longevity, than a city person has for a car (and those differing expectations also cause manufacturers to behave differently).

Modern electronics are a special problem since the chemicals used to manufacture integrated circuits cause the chips to degrade over time, even if not used or plugged in.

Much of the slackness in modern attitudes towards maintaining things for the long term comes down to economics. When my dad was growing up he would get in a *lot* of trouble if a wrench was not properly cleaned and stored at the end of the day, but nowadays people are far more careless. The reason is that 70+ years ago a good tool was expensive and an investment for a laborer, whereas today you can pick up a good wrench new for lunch money.

I have a 30-06 my grandpa gave me from around WWII... it would still be useful in 100 years from now, etc.

My cast iron pots and accessories.

My "brake drum" forge I`m building.

My granfrods bruks axe (spelling?).

P38 can opener.

Swiss army knives.