The ebb and flow of our website traffic is highly variable. It makes sense for many of the middleware functions to be serverless functions. The excitement is not about scaling up, but about scaling down!
In a traditional data centre we buy hardware based on a 3-5 year life cycle and inevitably we try and guess what traffic will be like in 3-5 years time and then for various regulatory reasons scale for 3x peak load. The risk is that we are way off in our guestimate and have paid a hefty sum for something we never need. We don't worry about the equipment not being powerful enough because in that scenario success is its own business case.
Serverless and cloud takes that all away. We only need to pay for what we are running at any one time. The challenge is to break down our applications so that serverless functions are an appropriate solution and also devising ways to have an automated testing regime for serverless functions.
Beyond serverless we have some folks getting very excited about uni-kernels. This is where an application compiles so that it is its own OS/app. In this world BCP would not sit on an OS that in turn handles all hardware (real or virtual) on the server. BCP would be the bit of the OS needed to read/write a file and talk to SQL Server. The vast majority of what an OS does simply isn't needed by BCP so would not exist. This means that uni-kernel apps are miniscule. You are talking about stuff with the memory footprint of an Atari 2600 game cartridge but running on C21st infrastructure!