Copyright is confusing. So confusing, in fact, that the only way to explain it is to turn to the bottle.
Or, rather, the humble bottle opener.
If at this point you're slightly confused as to what kind of bottle opener I'm referring to, seeing as there's quite a variety of mechanisms that can be used in the process of bottle opening, therefore deserving the name "bottle opener" - you're on point. There's more than one way to open a bottle, and there's more than one way to construct a bottle opener. The general principle being that if it opens bottles, it's a bottle opener.
The prevailing paradigm when it comes to enforcing copyright is to ensure that everyone uses a particular kind of bottle opener. No matter that there are many kinds of openers, many ways of opening a bottle and many bottle standards across the world - one solution fits all. And you have to use this particular opener in order to open the bottles you want to open.
The prevailing paradigm is circumvented every day. As you might imagine.
The key to making this enforcement strategy work is to design bottles in such a way that they can only be opened by a particular opener. Which is as hard to do in regards to bottles as it is to anything else, be it physical or digital objects. But, hard or not, the design efforts continue. Those who have the know-how to find other means of opening the bottles do so; those who do not, are left with the hope that the bottle/opener works well together.
And have to trust the ever so helpful customer services when they don't.
One example of this is libraries and ebooks. Especially university libraries. If you're a student, you most likely have access to a large number of ebooks through your library card. However, to actually use this access, you have to jump through some hoops. One of them being to log in with whatever student login is required. Another being that you are limited to using whatever format they are providing. Regardless if those formats actually work on the devices you use. Or the software you use.
Things only working in Internet Explorer, not working on mobile devices, only working for a limited time - there's a lot of demands and limitations to take into account. And it is up to you to adapt yourself to these demands and limitations, rather than the other way around.
Copyright demands that you use the prescribed opener. Which, in the library case, means that things are not as accessible and readable as the library ethos would want them to be. But they have to use these systems, because otherwise they wouldn't have access to these ebooks at all.
Copyright demands. Copyright limits.
It could be as simple as the book being there, available to everyone who'd want to read it, the world being a richer place for people having read it. It could be. But it isn't.
That's the most confusing part.