[ta0o0o0]

Interesting video, I just have a few nitpicks.

The problem is not that the piano has too many strings, it's that the notes are fixed. The same is true for any string instrument with frets, like a guitar, or wind instruments with fixed holes, like a flute.

The video also refers to the fact that equal temperament allows playing in any key, but doesn't really explain why that's important or what the tuning has to do with it. (Short answer, before equal temperament, different compromises were made in which notes were out of tune with respect to which others, and the schemes commonly chosen only allowed some of the keys (as in "c major" not the physical key) to be sufficiently in tune to be usable.)

[analog31]

As I understand it, people were aware of the problems of the temperaments, but a temperament is a technology. Each of the old temperaments came with an algorithm, that your regular Joe musician could use to keep their own instrument in tune. This in turn was needed because instruments didn't stay in tune for very long.

Equal temperament requires an expert, which in turn requires an instrument with stable tuning -- the modern piano.

Wind instruments actually have no straightforward temperament, but are just as close as possible, and the musician is expected to bend notes as needed. For all practical purposes, an orchestra is an un-tempered instrument.

[ta0o0o0]

OK. I guess I shouldn't have talked about instruments I don't know well.