They do, but under a completely different system than the way that they do for print books. When a library buys a print book, they can keep it in circulation for as long as they want and it's physically durable, but for digital, they're paying either per circulation or for an amount of time. They never own anything, they pay for temporary licenses, just like you never own the digital media you purchase in most cases.

The point that the person you're replying to is making is that this totally breaks the way libraries have always worked, and that it takes a lot of power away from the buyers (whether that's you or your local library) and puts way more in the hand of the publishers.

Even libraries can only license digital content for a limited period of time/loans before being forced to purchase new licenses. See https://www.spokanelibrary.org/the-true-cost-of-ebooks-and-a...

But those libraries have to pay each time they loan those digital goods. It's not the old "pay once loan until it's dust" model they use for physical goods.

can I donate my ebook to them?