That’s the thing, in a lot of cases you’d simply go without whether you wanted to or not. They use “savings” to illustrate how much it would have cost to buy all those books on their own, that’s it. They clearly wanted to read those books but they wouldn’t be able to afford them without a library. If they had the money to spend on them I’m sure they would have but they didn’t and that’s literally the whole point.

Not being able to afford something and not wanting that something are different and calling this “savings” is fine and makes complete sense.

—

Example: I’ve seen 1085 episodes of One Piece. Without Crunchyroll(and it’s low fees, compared to buying box sets I’d never rewatch) I’d never have been able to see all that content. I would have wanted to, but I couldn’t.

Or to mirror your own words more: Before Crunchyroll I never would have seen it as without the service to offer these savings I’d be shit out of luck.