This post is a copy&paste from a comment I posted on KVR where someone was arguing that 384kHz oversampling is a prerequisite for acceptably low levels of aliasing:
Oversampling a linear process (EQ) offers no benefit in terms of aliasing, because there isn’t any aliasing to get rid of.
Oversampling a time-variant process up to 2x is worthwhile, assuming an audio-rate (or lower) modulator, because you then have two spectra worth of audio content convolved together (spectrally speaking); I usually include dynamics in this category, since if your sidechain signal is generating a gain reduction signal that contains faster-than-audio-rate content, you are concerning yourself with compression-as-distortion, rather than compression as dynamics. I’ll take the point that the switch between attack and release might fall into this category, but as a designer of dynamics, we’d want to make that transition as smooth as possible. Or things would sound bad (e.g. Gate chatter, for instance).
Oversampling distortion is one easy way to ‘improve’ the sound of a naive distortion. Or even to add a little finesse to a good one. But of course, the degree of oversampling that’s beneficial is a function of the nature of the distortion, and how hard you hit it.
I’d like to speculate that most worthwhile, modern distortions are designed around an implicit oversampling-type process; runge-kutta being a good, topical example. But there are plenty of naive distortions around, and without oversampling, they sound terrible. I don’t know how it’s still a thing, but seemingly it is. I suppose the key factor is that aliasing is ALWAYS going to be a LOT quieter than signal, so it’s going to remain “grab the spec analyser” kind of problem. (Except in Massive, where the aliasing is what makes it good)