I forgot if I shared this story from three years ago. It still is very
fresh in my memory.

Three years ago, I sold a completely unremarkable, used and beat up,
but working, "Sioux tools" air grinder on ebay. The buyer's email
address indicated that he is with Sioux tools. After he left me a
positive, I asked him, how come he bought this really old tool, when
they make new ones?

His answer floored me. He said that they occasionally buy old tools on
purpose, to evaluate how they wear, what parts and bits in them need
improvements to last longer for their future versions, etc.

This is so unusual.

The usual attitude, nowadays, is that if the tool lasts beyond the
three month warranty period, everything is great. Apparently, Sioux
tools does not think so and wants their toold to last forever.

i