[aidenn0]

Discrete power MOSFETs are only switches. Discrete linear-stable MOSFETs are also usable as linear amplifiers. TFA is about mosfets on ICs. When making your own ICs, you have precise control over a lot of the variables, and the variables you have less precise control over are often going to be very similar for adjacent FETs on the same wafer, so you can do things with them that you can't do with discrete MOSFETs.

[MisterTea]

What stinks is that linear use has waned so much that most lateral mosfets are no longer produced. Everything is vertical switching for PWM control.

[aidenn0]

Wow, you aren't kidding. I just checked Onsemi and Vishay and neither makes lateral mosfets anymore. I'm surprised because many audio amplifiers still have a linear output stage, are those just always BJTs now?

[MisterTea]

Most of the linear amps these days are integrated devices that need a few supporting components and you feed a line level audio signal. Though you can still get decently sized BJT's and you can build your own amps.