[kmbfjr]

You raise an interesting issue to which I offer just ONE counterpoint. That is, a 555 circuit often requires external circuits that involve useful theory beyond basic circuits.

I’m thinking RC timing and voltage dividers. These have practical application. Would it ever get used elsewhere? That is where my thinking merges to yours.

Forty years from when I started that journey, not sure it can’t be learned from a wiki.

[15155]

Voltage dividers are still commonly used in MCU-laden designs, as are RC timing circuits.

(The power supply sitting next to that MCU has a divider-based feedback loop, usually.)

These possibly can't be learned from a wiki, but they can absolutely be learned from the Art of Electronics for a low price.

[wkjagt]

A potentiometer is a simple voltage divider, and I think often used as an input to the ADC of an MCU, as a means of turning some some value up or down.