That's what I said. Read my post again. The content has to suit the amplifier or it all goes pear shaped. That's the difference, preamplifiers and power amplifiers were able to cope with anything up to low level RF and do what they should- amplify without adding or subtracting anything. There was no 'rubbish' going on up top to cause trouble in the baseband.
Take the 1978 Kenwood L07c. I used to use one on my bench for high level square waves in between my signal generator and attached device as it could swing another >30V more than my signal gen. Up to 100Khz the rise time barely suffered. It was amazing- like a instrumentation amplifier. It's matching power amps were insane. There's a Perreaux 2150B in my storeroom which runs out to 3MHz at unity gain- that's insanity.
So, why is it OK for Class D proponents to justify chasing ever decreasing levels of THD as their headline point of difference, well below the limits of audibility, and at the same time throw water on people justifying wide bandwidth amplification? Hint, it's not OK.
Read my post again, it's about the message and the justification sold to audiophiles and the attempt to subvert/divert and re-cast Class D in a different light by channeling the old UK amplifier designers of old where bandwidth limiting was the new black- until it wasn't.
Remember when CD-4 and other multichannel LP sources were devised? Bandwidths were expanded, capacitor coupling was thrown out and we got high speed diffused emitter, RETs, and the ability to do part time LW transmission with our power amps (kidding). Along came DC-Daylight for all things amplification related.
CD strawman nothwithstanding, is it OK to just say for once that Class D amplification does really, really well in the audible bandwidth and not outside it? Again, Class D doesn't have to be your own personal crusade, we already have one of them here (he's back).