The big change going from WASI 0.1 to WASI 0.2 is that we decoupled the calling convention (Wasm Components) from the actual syscall APIs (WASI). That enabled us to make the various syscall APIs modular and composable.
Because CDN functions probably shouldn't know about TCP; and CLI applications probably don't care about blob storage. And now they don't need to. Take a look at the WASI Proposals page [1] for an overview of all WASI APIs.
[1]: https://github.com/WebAssembly/WASI/blob/main/Proposals.md