Value of a preamp?

It can greatly improve the overall performance of a system. 

The ’preamp’ is essentially a cash grabbing strategy 

Yeah, no.  That’s just ridiculous.

So when all the impedance values are matched up correctly with a passive attenuator, then a more true to the source sound is being heard.

@scm So then it becomes, when are all those pesky impedance values matched up correctly?  Impossible to know, so just use your ears.