I always wonder about this scalability part: >resources used on serverless frameworks are typically paid for by the minute (or even by the second). This means

I always wonder about this scalability part: >resources used on serverless frameworks are typically paid for by the minute (or even by the second). This means that clients only pay for the time they are actually running code. This contrasts favorably with the traditional cloud-based virtual machine, where often you end up paying for a machine that sits idle much of the time. I'm going to ask something very stupid because I'm very ignorant but... when do you need this? In my mind you have scenario 1: the app never runs because no users, so running it 24/7 is a waste. In this case why cloud? Pay $5 a month for a simple web host? Scenario 2: you are hitting 100% on a server and you need a second server but that second server will only use 1% most of the time. Again, why not just upgrade the server with your web host? Scenario 3: you have a bajillion users on peak hours and a tenth of a bajillion on other hours. I assume you would have a business model that affords you to hire someone to manage scaling your infrastructure? What am I missing in this picture?