you’re very conveniently ignoring the “material objects” part of that definition
I’m not, it’s just that the wording of the definition could lead to you interpreting it as such. It does not mean what you think it means.
In essence, it’s saying that if a material object is “fixed” (under copyright law, that tends to mean captured in a medium that allows it to be perceived, reproduced, or otherwise communicated) it is considered a copy. Copyright law generally considers things like written texts (i.e. transcribing a book onto other sheets of paper) to be copies, but it also includes things like recordings, which are very much nontangible. (although still stored on tangible hardware) Also, note the “either directly or with the aid of a machine or device” section of that description.
DRM is entirely irrelevant. It has no bearing on anything.
The fact you consider DRM to be irrelevant in a conversation about managing legal access to digitally distributed content shows a lot about your understanding of this topic, to say the least.
DRM is highly relevant. If it were not, then all libraries would already be illegally publishing copies under the agreements they sign with publishers when they distribute books through DRM-protected applications like Overdrive or Libby. Legal consequence also does not extend past the original publisher if the intent was clearly not to deliberately allow for further copying. (i.e. if the Internet Archive stated they lent books so users could copy them and later share them with friends, that would be a violation. Instead, they have loan terms, limits, and DRM)
If anything done by a user after the lending of any material, outside of reasonable safeguards (like DRM) was to be considered illegal, then any store would be liable if someone used a kitchen knife to kill someone, and any chemical distributor would be liable if someone in a lab mixed the wrong chemicals together and made an explosion. Liability has an end point, and DRM helps signify that by placing technical restrictions on redistribution of material, while also carrying heavy legal penalties for breaking it, which would not be present if it wasn’t applied in the first place.
Publishers should not be able to sue libraries for lending their books, digital, physical, or otherwise. Especially when the publishers could not demonstrate any material harm.
You are actively defending multi-billion dollar publishing companies suing a library for lending content they legally acquired, using faulty interpretations of the law, and deference to lawsuits as a means of judging the morality of actions. You haven’t made a single point that wasn’t either verifiably untrue, or misinformed.