Transistors

[ppppenguin]

I'm sorry but I have to disagree, the relationship between collector current and base current is reasonably linear over quite a wide range.

And the ratio is very uncertain.Varies widely with temperature and with different devices. I can't imagine how you would design an amplifier or anything else by relying on the current gain.

Whereas the voltage gain is utterly predictable, varies only slightly with temperature and can be approximated as linear for small signals.