Say what you want about the current copyright system, but buying a single book and lending it out one at a time and buying a new one when it wears out, is obviously different than handing out unlimited digital copies.
Imagine this:
"Good news, everyone! We've invented Star Trek-like replication technology. I can replicate and provide any amount of food or tools for everyone! It's the post-scarcity society we've always dreamt of!"
"Quick, we must now devise a way to make this encumbered so food and tools cannot really be replicated at will with zero cost, and instead make it resemble how we used to farm/grow food and build traditional tools, or else business as we know it may crumble. Also we need a way to identify and sue people who breach our business contracts!"
It's depressing. A bit like the future that The Murderbot Diaries depict.
We have to stick with the old way for now, otherwise it would only take one library buying one copy of anything, and it being available to any and everyone on an unlimited basis. That can't work.
It's depressing when people argue "but libraries can only lend as many physical copies as they have" as if this was a good thing about books instead of an accidental limitation.
Actually, that's the concept I was looking for: accidental limitations. It sucks when publishers and media companies seek to turn accidental limitations into mandated limitations, as if they were a law of nature, and when the technology could rid us of said limitations.
Likewise, painters will paint even if nobody will buy their paintings.
That's art for you.
Isn't there an ongoing lawsuit against Amazon on this issue where someone is suing them for misguiding people about ownership when you "buy" an ebook from them?
[0] https://goodereader.com/blog/e-book-news/this-is-the-big-rea...
Of course much legal machination will be attempted to assert you don't.
YMMV.