> Exists precision resistors with accuracy +-0.5%, or even 0.1%, but high precision applications, typically used some very different technologies. For example, are high quality multi-turn variable resistors, laser cut resistivity pads, created with high cost materials or even rare-earth materials.

Most modern resistors are of either a thin-film type, with sub-micron-thin layers of nickel directly sputtered and onto a ceramic body, or a thick-film type, with a metal oxide/ceramic paste applied and baked onto the ceramic body.

The process window is aimed at a target, but binning operations after production are all that separate precision resistors from cheap resistors.

If you sputter on a little too much nickel, or your paste isn't quite as conductive after baking as you hoped, you just sell that one as a 10% or 5% resistor.

If you get lucky, and produce one that is within 0.01% of an E96 resistor (which might even happen while aiming for an E12 resistance!), you sell it as a precision unit.

Agreed that these aren't that important in most modern designs.