I know you are speaking of just the *recording* (digital conversion step inside the converter's electronics) but there are many arguments about this converter is better than that converter, and yeah, it may not be the actual *digital* conversion that imparts some flavor, and it's most likely the analog filtering...but still, when people judge a converter it's the whole package.
Mind you, I'm not one of the digital haters...
...I've settled into a very nice hybrid setup, and I don't really have a lot of bad things to say about digital, I just prefer the sound of tracking and mixing in analog, OTB...though the DAW absolutely kills for edits and comps.
But here's the thing...and this may be getting away from the more simplistic consideration of just the digital conversion step....for many folks who use digital it's MUCH more than just about a conversion step from analog. It's the use of a particular DAW, and lord knows, there have been many comments about one DAW having a better "audio engine" (aka digital algorithm process) than another DAW. It's also the use of dozens and dozens of digital plug-ins that each add or take away and have their own algorithm process (some bad some good). Plus, there's the summing and conversion back out to analog for listening, which is a bit different than the recording/tracking process...and again, not all DAWs and converters do that the same way.
So...when you talk about digital and say
"Essentially, it neither adds nor takes away"...that is not a realistic view, though again, I know you are talking about just the *conversion step*, but it really can NOT be looked at apart from the rest of the converter's design or the rest of the digital processes most people use.
I look at digital in the same way as I would look at another microphone, or another preamp, or a different analog console. In the analog world, most every piece has some flavor to it...and IMO, digital is no different, and that's really my point, digital is not bad or good, no more than console A or console B....rather it's just another flavor, and yes, taken as a whole, digital processes DO impart flavors on the original sound when you get to the end result of your production.
Also, while for some it may be the case...for me, *accuracy* is not necessarily the main focus of recording. In most cases with any type of production regardless of format and medium used...the final result is rarely just an attempt at an accurate "capture" of what went down in the studio, and instead it's an adjusted and tuned *representation* and an attempt at a bigger picture...than just a documentation of the original.
Not much different than an impressionist painting would be, though photography has it's beauty too, but it's also a *conversion*...and that's what digital is a *conversion* from the original, and so is analog for that matter.