Compiling every dependency into a single WASM binary (including database engine, language runtime, etc) and just deploy and scale it on a serverless platform.
No more containers to develop or to deploy, and eventually, no UNIX filesystem around the runtime.
This, WASM, some virtual OS API, and edge deployment (5G), even on user devices. Also some energy efficient blockchain mechanisms and smart contracts may bring us closer to trusted computing. Although that won't happen quickly enough, not next after K8s.
I'm thinking of this as well. Given how frontend frameworks like Svelte are moving towards a "framework as compiler" approach and how newer runtimes like are Deno now support compiling to a self-contained standalone binary, my guess is that WASM will become the main target for cross-platform development.
No more containers to develop or to deploy, and eventually, no UNIX filesystem around the runtime.