Right, like my bedroom light switches were designed for my bedroom light. Much different than my dining room light switch.
A transistor is simply a switch. It can also amplify a signal. It can be used in the design of an amplifier, but nothing can make it designed specifically for audio. It is simply the switching and amplification properties can be adjusted to fit the circuit that is being designed. All amp that use GANFET (Gallium Nitride field-effect transistors) use a GANFET designed for audio. The audio equipment it is in.