would really like to see serverless functions based on unikernel instant starts. containers are a great way to integrate functionality like that into kubernetes.
What made me stop believing in this was WASM/WASI. When it matures it will have similar performance, far better start-up times (microseconds) and a superior transport in/out of the application - WASI is a lot more convenient compared to serial ports and ethernet, which are how a unikernel normally talks to the world.
I still think unikernels are a good idea, but, imo, serverless functions isn't a valid use-case anymore.
What might hinder unikernels, is that chiseled containers is already halfway there.