The clock sources in modern electronics seem to come invariably from quartz and MEMS oscillators, both of which generate vibrations mechanically. The amplitude and frequency of the vibration are orders of magnitudes different from the everday mechanical vibrations I observe in, say, musical instruments. Nevertheless, it's surprising to me that we don't get clock sources in the electromagnetic domain directly, say using capacitive or inductive elements.
I know that inductors especially are hard to manufacture without parasitic losses. But I would expect mechanical oscillators to be non-ideal as well.
You could use the propagation delay of electricity, but then it would be hard to make a small oscillator that operates at slow frequencies.
Is it really true we can make microscopic vibrating devices more ideally than we can make electrical oscillating components?