Notices by Optional (optional@dice.camp)

Can somebody explain to me why I can't simply buy an audiobook, but instead have to subscribe for credits, which can be exchanged for audiobooks?
Who decided that audiobooks are not a product, but that buying audiobooks is actually a service for which I should be paying?
Like, I have money and you have a product I want. Why make it more complicated than buying literally anything else?

I'm genuinely interested in answers.