Nice of you to assume that I don't understand the pricing of the services I use. I can assure you that I do, and I can also assure you that there is no such thing as provisioned vs on-demand pricing for Azure App Service until you get into the higher tiers. And even in those higher tiers, it's cheaper for me to use on-demand capacity.

Obviously what I'm saying will not apply to all use cases, but I'm only talking about mine.