[SiempreViernes]

Well, old things still around today were usually built to last which is rather natural. (There are rare exceptions, the Eiffel tower was meant to stand only 20 years)

[huffmsa]

We do have a bit of a sample bias. We only see the things which have survived. But planned obsolescence was the norm.

Technology advanced too slowly for a producer to assume they'd have a new model to sell in the near future.

[CharlesColeman]

Exactly, which is why we should think twice about replacing them, just for the sake of having something newer. Newer isn't always better.